In Muted, Scott met Liam for the first time when Scott and Stiles arrived at morning lacrosse practice, where Liam dominated on the field. Scott and Stiles were shocked and somewhat jealous of Liam's abilities, to the point where Stiles was sure that Liam was already a werecreature. After they overheard one of their teammates, Garrett, say that Liam could possibly be their first freshman captain, Scott and Stiles decided to get serious about lacrosse (a hobby that had fallen by the wayside due to the supernatural drama they experienced over the last year) so they could keep him from taking Scott's position as team captain.
At Stiles' urging, the two confronted Liam in the locker room after early morning practice to ask him how he got so good, as Stiles was sure that Liam was a "werecheetah" or something similar. However, Liam simply stated that he learned how to play from his step-father, Dr. Geyer, and though Scott caught him in a lie about getting kicked out of his former school, Devenford Prep, he determined that Liam was human and left the matter until that afternoon's first lacrosse try-outs.
Scott viewed using his werewolf powers in lacrosse as cheating, but unfortunately, relying solely on his human abilities left much to be desired in his lacrosse performance, and he became so intent on retaining his position on the team that he and Stiles accidentally injured Liam during two-against-one drills. Upon seeing that Liam's ankle was possibly broken, Scott and Stiles took Liam to the hospital to be treated by Liam's step-father, Dr. Geyer. Scott stayed at the hospital to find out how Liam was doing and overheard a conversation where Liam mentioned that he was trying to show off to Scott, who, like Dr. Geyer in his youth, was team captain as a sophomore, something that only made Scott feel more guilty about injuring him and letting his jealousy get the better of him.
After finding his mother, Melissa McCall, being attacked by a Wendigo named Sean Walcott who had been admitted to the hospital after his family was killed by an assassin known as The Mute, Scott spent a moment checking on her before chasing after Sean, who had snatched Liam from outside his own hospital room before dragging him up onto the roof to eat him. Scott, in his full werewolf form, pleaded with Sean to let Liam go and promised to help him, but when Sean refused to relent, Scott attacked, and Sean shoved Liam so hard that he toppled over the roof and barely managed to grab the edge with his fingers to avoid falling five stories and onto the ground below. Scott struggled to incapacitate Sean long enough to save Liam, and when he attempted to pull the boy up, Sean pulled Scott's arms behind his back to stop him, leaving Scott no choice but to prevent Liam from falling by grabbing his forearm with his fangs before he plummeted to his death. Sean was then killed by The Mute, who left before Scott could figure out who he was, but the damage to Liam had already been done-- Scott had bitten Liam hard enough to either turn him into a werewolf or kill him.
In The Benefactor, a frantic Scott called Stiles over to his house, where, much to his embarrassment, he confessed to having brought Liam home and duct-taped him up in his bathtub, as he had panicked regarding what to do with him after having accidentally given him the Bite. Stiles was appalled, but ultimately decided to help Scott break the news to Liam about what could be happening to him. Unfortunately, Stiles handled the situation in his typically tactless manner by bluntly telling Liam that he could die, leading Liam to fake-cry in order to manipulate them into removing his restraints before he smashed a chair over their heads and attempted to escape. To his shock, he found that his ankle had already healed due to the approaching full moon, indicating that he was successfully transforming, and he ran home before Scott and Stiles could catch him.
The next day at school, Liam started to feel sweaty and woozy, worrying his best friend Mason Hewitt. He was once again ambushed by Scott and Stiles, who urged him to listen to them because of the seriousness of their current situation. After Scott made the mistake of channeling Derek Hale by telling Liam "The Bite is a gift," and "We're brothers now," (see Wolf Moon) Liam ripped off the bandage on his arm where Scott bit him and insisted that nothing was happening to him, revealing that the bite had already healed and that he was becoming a werewolf. At a loss for options, Scott, Stiles, Lydia, Kira, and Malia decided to lie to Liam and tell him that they were having a party at Lydia's family's lake house in order to help him through his first full moon, whether he wanted it or not. To do this, Kira attempted to draw on her trickster nature to get Liam to have a crush on her so he would accept her invitation to their "party" so he wouldn't know Scott and Stiles were involved.
Right before Liam was set to arrive with Kira, Stiles came to Scott and informed him that he had finally learned why Liam had been kicked out of Devenford Prep-- he had viciously demolished his teacher's car with a crowbar and scratched "THIS IS YOUR FAULT" in the paint. Scott became even more worried about Liam's future as a werewolf due to his pre-existing anger issues, but continued on with the plan. Once Liam arrived, they gave him what they called an "intervention," to which Liam reacted predictably badly. However, he was quickly overwhelmed with the power of the full moon and started to transform, leading Scott and Kira to rush him out to the boat house to lock him up, leaving Stiles and Malia to deal with her transformation in the basement and Lydia to deal with the party-crashers upstairs.
Liam proved incredibly difficult to lock up due to having an unprecedented level of strength for a neophyte werewolf, and when he started to attack Scott, who didn't want to fight back out of fear of hurting and scaring him more, Kira was forced to hit him with a boat oar, which knocked him out and allowed them to chain Liam to one of the support beams. Kira worried that Liam wouldn't want their help, but Scott assured her that he would, because he went through the same thing himself. However, when Liam awoke, he fully transformed into a werewolf and used his enhanced strength (even more augmented by his anger) to break out and run into the woods. Scott finally managed to catch up with him, only for Liam to attack him once again until he was stopped by the appearance of Chris Argent, who shot a flash-bang arrow and scared Liam away. After Chris encouraged Scott to use his own words to get through to Liam, he sent Scott off to a trap he had made with ultra-sonic emitters, which had trapped Liam and caused him enough pain to transform him back into a human.
When Scott found him once again, Liam asked him what was happening to him, and Scott grimly informed him that it was the same thing that happened to him. Liam began to panic and begged Scott not to let his mother and step-father see him like this, because he couldn't stand to make them see him as a monster like they did when he destroyed his coach's car and got kicked out of school. Scott then replied, "You're not a monster. You're a werewolf... Like me." This comforted Liam enough to finally return to the lake house, and he began to accept his lycanthropy.
In I.E.D., after working out in the weight room at school and being forced to lie to his best friend Mason about his transformation, Liam went into the locker room and found, much to his anger, that his lacrosse stick was gone. He then picked up the sound of a lacrosse stick dragging against the lockers and turned to see Derek Hale (who he had not yet met) holding his lacrosse stick.
When Derek asked him if it belonged to him and snapped it in half, Liam's eyes flashed gold, leading Derek to simply beckon him to try to fight him. Liam lunged for him, but Derek, being older and more experienced, easily grabbed him in a choke-hold and pinned him to the row of lockers. Liam snarled and snapped at him with his fangs until Scott appeared and called his name. The sound of his Alpha's voice calmed him down, and when he realized that Scott knew Derek, he made an angry face as Derek let him go, remarking that Scott was right about Liam being strong. Scott informed Liam that he had his stick, and that Derek had broken one of the school-provided ones, before sending him off to class. Once Liam had left, Derek smiled and said that Scott was going to be good at being an Alpha, and though Scott expressed concern that he wasn't experienced enough to have his new Beta, especially considering everything that was happening with the Deadpool and Kate Argent's return, Derek assured him that they would get through it one issue at a time.
That afternoon, Scott and Stiles watched from a distance as the Devenford Prep lacrosse team arrived at their school, and became concerned when they saw Liam approaching Brett Talbot, a former teammate. They worried that Liam was going to try to attack him, but were surprised to see Liam extend his hand to wish Brett a good game. However, when Brett brought up Devenford Prep's coach and how Liam destroyed his car, Liam became so angry that he squeezed his hand into a fist, causing his claws to cut his hands. When Scott and Stiles overheard Brett tell him that they were going to make him pay for what he did, they rushed over to grab Liam before he could get into a fight or expose his powers. They then rushed him into the locker room just as he transformed out of anger, where they shoved him in the showers and doused him in cold water until he shifted back.
After he calmed down, Scott asked Liam what happened with his coach, and Liam explained that his coach benched him for the entire lacrosse season after he got too many red cards, and that he lost himself in a rage, which is why he destroyed his coach's car. Afterward, Liam was kicked out of school and sent to a psychologist for an evaluation, where he was diagnosed with intermittent explosive disorder, or IED. When Scott asked him if he was prescribed anything for it, Liam admitted that he was given Risperdal, but that he quit taking it because it made him too tired and he wasn't able to play lacrosse.
Stiles implied that Scott made a mistake by turning Liam into a werewolf when he was already literal walking time-bomb, but Scott disagreed, though he did suggest that Liam bail out of the game just in case by telling Coach Finstock that his leg was still hurt. However, Liam, who seemed to have grown to both like and trust Scott since his transformation, insisted that he could play, especially if Scott was there to help give him moral support. Scott expressed his concern about the Deadpool assassins and the fact that they still didn't know who killed Demarco Montana, the keg delivery man, at Lydia's party in the previous episode, but Liam realized that while he didn't know who ordered the keg, he did know who paid for it-- Garrett, their fellow teammate.
That night at the game, Scott and Stiles had to stop Liam from angrily attacking Brett on several occasions, particularly considering that Devenford Prep was dominating them in points. In the middle of the match, Brett, Garrett, and Liam all tackled each other so hard that Liam broke his arm, and when Scott and Stiles helped him up, Scott caught Garrett retracting a wolfsbane-coated blade from inside his lacrosse stick and assumed that Garrett was trying to kill Liam, since they had only cracked one-third of the Deadpool hit-list and were concerned that he was on one of the other two lists. However, after determining that Liam had not been cut by Garrett's blade, Scott used his hands to set Liam's broken forearm while Brett, who was beginning to look delirious as he loudly cried out in pain, was taken inside by the medics for treatment for his injuries. Near the end of the game, Scott and Liam were standing together and discussing the day's events when Stiles came up to them with their phone out and informed them both that Lydia and Malia had cracked the second portion of the Deadpool list, and while Liam wasn't on it, Brett was.
In Orphaned, Liam met up with Scott after Violet attempted to kill him to inform him that Kira had left after learning that her mother, Noshiko Yukimura, was on the the second portion of the Deadpool list. The two then eavesdropped on Scott's father, FBI Special Agent Rafael McCall's conversation with Violet about the fact that she and Garrett were two assassins known as The Orphans. Afterward, Liam kept watch outside the locker room while Scott searched Garrett's locker, though Scott kept the fact that he found Garrett's duffel bag full of $500,000 from killing Carrie Hudson inside of it.
The next day, Liam went on a run with Mason and vaguely mentioned being stressed out about the revelation that their so-called friends Garrett and Violet were just using them to get to their assassination targets. Liam got carried away in running and ended up far away from Mason due to his enhanced speed, where he was run over by Garrett in his SUV. Garrett walked toward Liam with his forked blade, still coated in yellow wolfsbane, and stabbed him in the chest with it before throwing him in a well in the Beacon Hills Preserve. After Mason lost track of Liam, he went back to the school to find Scott in order to learn whether he had seen him recently. When they went to Coach Finstock and learned that Liam had missed his class, Scott assured Mason that he'd let him know when he got in touch with Liam.
It was just after they separated that Scott got a call from Liam's phone, but when he answered it, he found that it was actually Garrett, who told him that the only way he was going to get Liam back was if he met with him outside in the bus bay. Once there, Garrett informed Scott what he had done to Liam and warned him that if the yellow wolfsbane got to his heart, he would die. In order to save him, Garrett wanted Scott to not only give him the money back that he stole, but to also get him Violet back by breaking her out of the armored car before she was taking to a federal prison for her crimes. Though Scott was not keen to help Garrett, he was desperate to find and save Liam, and as a result, he agreed to his plan. All the while, Liam desperately tried to get out of the well by climbing up the bricks, but every time, he slipped and fell back into the water.
Scott and Garrett followed the armored car, only to find that it had already been stopped and overturned by Kate Argent and her Berserkers, the former of whom captured Violet and took her away, leaving her Berserkers to deal with Sheriff Stilinski, Agent McCall, Scott, and Garrett. Garrett was ultimately killed by a Berserker while the other stabbed Scott with his claw, though fortunately, he was saved by Chris Argent, who was tracking Kate, and brought back to the animal clinic to be treated by Alan Deaton. After he came to, Scott insisted that he had to find Violet, since she was now the only hope of finding Liam, and used the Berserker claw they left in his side to track them to Argent Arms International, where he was accompanied by Chris.
The two went into the warehouse and fought against Kate and the Berserkers, and after Scott was thrown into a wall, he found Violet was already dead. After Kate called off the Berserkers and fled, Scott went back to Chris and lamented the fact that he was never going to find Liam, but Chris assured him that there was still hope. Just then, Liam, who had made it just a few feet from the top of the well, instinctively roared as loud as he could, allowing Scott to find him and pull him back. Once he was out, Scott hugged him and assured him that he was okay before bringing him back to the animal clinic so Deaton could drain the wolfsbane from his body.
In Time of Death, Scott and Liam were joined by Kira and Stiles so that they could all figure out a way to lure The Benefactor out of hiding and finally learn his or her identity. To do this, Scott, who was the most valuable target on the Deadpool at $25 million, decided to use himself as bait by faking his death and making it seem as though visual confirmation was impossible to gain so that The Benefactor would have to come to see for themselves. Liam, however, was immediately concerned about this plan and pointed out how dangerous it was before asking Scott and Stiles if they had ever done something like this before, though it was implied that they most certainly have.
Liam was present that evening in Scott's bedroom at the McCall House, where he and Kira were supervised by Noshiko Yukimura, who had experience in what Kira was planning to do and reluctantly agreed to help them. Liam asked Noshiko a lot of questions about how Kira would be stopping Scott's heart, and when it became obvious that Liam was extremely worried about the fact that Scott could actually die during this attempt to fake his death, Kira told Scott to tell Liam that everything would be okay, which he did. Liam then watched as Kira used her foxfire to slow Scott's heart to one beat every few minutes.
Liam, along with Kira, Stiles, and Noshiko, then met Melissa McCall at the hospital's morgue, where they all stood vigil around Scott's body. Liam looked concerned as they informed Melissa of what they had done, and became even more so when it was revealed that Scott would die if he wasn't brought back within 45 minutes. In order to keep Scott safe while he was essentially "dead," Liam, Stiles, and Kira hooked up their laptops to the hospital's surveillance cameras with help from Chris Argent, who was physically guarding Scott's body, in order to catch the Benefactor before they could claim Scott for the Deadpool. When the camera feed on the roof was mysteriously cut off, Liam, eager to help protect Scott, accompanied Kira to the roof to investigate, where the two eventually ran into one of Kate Argent's Berserkers. Liam didn't return to see Scott until after he was awakened, where he regretfully informed Kira of her mother's injuries at the hands of the other Berserker.
In Perishable, Liam began suffering symptoms of acute traumatic stress disorder after his run-in with the Berserkers in the previous episode, including hallucinations of them following him around that caused him to have panic attacks and insomnia. To make matters worse, his printer mysteriously began printing out revised versions of the Deadpool hit-list, where his value was increased from $3 million to $18 million, making him the third most valuable on the list after Scott and Lydia. Scott, recognizing that something was bothering his Beta, approached him at school and asked him what was wrong, causing Liam to admit what he had learned about the Deadpool. The two were also present when Coach Finstock's own printer began printing out copies of the revised Deadpool as well, leading them to realize that Derek Hale, who was believed to be losing his werewolf powers, was no longer on the list, and the value of his bounty was added to Liam's.
That night at the lacrosse bonfire, Scott approached Malia to try to apologize for hiding her true parentage from her, and when he awkwardly informed her that, as werecreatures, they could not get drunk off of alcohol, Malia gestured to Liam, who was drinking heavily from a bottle of vodka mixed with soda, and told him to tell Liam that. Scott became incredibly concerned when both Liam and Malia began exhibiting symptoms of being drunk despite their healing ability making that impossible. However, it wasn't until Scott himself began feeling the symptoms that he realized it wasn't the alcohol that was affecting them, but the subsonic frequencies in the music played by the DJ, who was secretly working with cohorts of Deputy Haigh, the deputy who had tried to kill Jordan Parrish the previous night.
When Mason Hewitt expressed concern for Scott, Liam and Malia's current state, Scott vaguely explained that the music was affecting them and that he needed to turn it off before instructing Mason to not let Liam or Malia out of his sight. However, the DJ turned up the music when Scott got close, allowing him to be captured by the corrupt security guards working with Deputy Haigh, who overpowered Mason and captured Liam and Malia soon after. With Scott, Liam, and Malia too weakened by the subsonic frequencies to fight back, the dirty security guards dragged them into the high school and doused them in gasoline in preparation to burn them like Haigh attempted to burn Parrish. Fortunately for them, Mason remembered what Scott had said and disabled the music, allowing Scott to overpower one of the guards long enough for Derek Hale and Braeden to show up and rescue the three before they could be killed.
In Monstrous, Liam got cleaned up at the McCall House with Scott after their most-recent near-death experience. However, when Scott informed him that Kira had found Brett Talbot, his sister Lorilee, and the rest of the survivors in Satomi Ito's pack, Liam clammed up and stopped following him, leading Scott to realize that Liam, still being a new werewolf, was having difficulty dealing with the extreme levels of stress that followed around the supernatural community of Beacon Hills.
When Scott offered to take Liam home instead of bringing him with him to the animal clinic, Liam quietly reminded Scott that he wasn't like him. Scott assumed he was talking about having control over his lycanthropy and assured him that he might not be yet, but he soon would be, Liam explained that it wasn't what he meant and said that it was everything else, including the fact that Scott and the McCall Pack are constantly trying to save everyone. When Liam asked him if they've always done this and wondered aloud how they were all still alive after everything they've been through, Scott sadly informed him that not all of them had survived before gently handing him his spare motorbike helmet and offering to drive him home once again, an offer Liam accepted.
In A Promise to the Dead, Liam continued to suffer from acute traumatic stress following his battle with the Berserker, which led him to have insomnia and terrifying hallucinations that he was being followed by the bear-like creatures. At school the next day, Liam was in the weight room with Mason, where the two were working out together. It was clear to Mason that something was wrong with him and expressed concern when Liam loaded hundreds of pounds of weight to the bench press.
Clearly in a bad mood, Liam snapped at him that he could handle it and did several reps to prove his point; however, after Mason turned away from him, Liam returned to doing reps on the bench press as his mind flooded with flashbacks of his battle with the Berserker, causing Liam's super-strength to temporarily give out and pinning him under the bar. Fortunately for him, Scott sensed his anxiety and fear and rushed into the weight room, pulling the barbell off of his chest so Liam could breathe as Mason watched in shock and concern. Scott whispered to Liam that it was completely fine if he didn't want to be in the pack, but that he shouldn't push away friends like Mason, either.
That evening, before the lacrosse game started, Liam approached Stiles in the locker room and expressed concern regarding Scott and Kira's lateness, not knowing at the time that the two had been attacked and captured by Kate Argent and her Berserkers before being taken to Mexico. Stiles, knowing that the two had a date planned at Derek's loft, assured him that he would be there, and he and Liam helped cover for Scott when Coach Finstock also noticed their absence. When the game started and Scott was still nowhere to be found, Liam only grew more concerned, and continued to question Stiles about what was going on. Stiles assured him that it wasn't a big deal, but secretly texted Scott to tell him that he was very worried. Liam's stress about Scott's well-being increased his anxiety about the Berserker battle, and he began to hallucinate that the Berserker was killing Brett Talbot on the field, causing him to nearly have a panic attack until Brett snapped him out of it.
After the game, Brett approached Liam to ask him if he was okay, and when Liam asked him why he helped him despite their dislike for each other, Brett confessed that it was because Scott had saved him, his pack, and the rest of the survivors of the Deadpool. He pointed out that Liam didn't know how lucky he was, because Scott, as a True Alpha, earned his power and status rather than stealing it or inheriting it, and that both Liam and Scott weren't strong because they were werewolves, but because they endure, which he said Satomi called "strength of character." He then reiterated that Liam was lucky to have Scott before he left, leading Liam to mutter, "Then why isn't he here?"
In Smoke and Mirrors, Liam, upon learning that Scott and Kira had been captured by Kate Argent and taken to La Iglesia in Mexico, immediately rushed to the McCall House to offer his assistance to Stiles and Malia, who were searching his bedroom for something to get a stronger scent. Though he appreciated Liam's offer, Stiles declined, reminding him that he had only been a werewolf for a short time and that the full moon that night would cause him to lose control and only cause more problems. Despite this warning, Liam was insistent upon helping his Alpha and suggested that Stiles and Malia chain him up in the backseat of whatever vehicle they took, but Malia pointed out that he broke through the chains they had during his first full moon. However, after Liam continued pushing, Stiles got an idea as to how to bring Liam along with them, since he and Malia knew that they needed all the help that they could get.
The three then met up with Braeden and Derek, who had used Braeden's US Marshal credentials to get a prisoner transport van so that they could lock Liam up in the back. Also joining them was Peter, who warned them about the dangers they faced in saving Scott and Kira from Kate and the Berserkers. On the way to La Iglesia, where Kate was keeping Scott and Kira, the moon rose in the sky and caused Liam to transform, nearly killing Derek and Stiles, who were in the back of the transport van to supervise him. Fortunately, they managed to get him under control by using Satomi's Pack's mantra, and once he had calmed down, Derek asked him if he could continue exhibiting his control in order to save Scott and Kira, which Liam insisted he could do.
Leaving Braeden and Derek outside of the church due to Derek's injuries at the hands of a Berserker, Liam, Malia, Peter, and Stiles entered the temple in search of Scott and Kira. When they ran into another Berserker, they split up, with Liam, Malia, and Peter attacking the Berserker while Stiles left to get Kira. The three then engaged in a fierce battle with the beastly creature for quite a while until Liam and Peter were able to pin it to a wall, leading Peter to encourage Malia to stab it in the skull with its own bone knife. However, when Kira and Stiles rushed in and informed them that the Berserker was Scott, who had been transformed by Kate, Liam, stunned, looked into the eyes of the person behind the mask and recognized Scott for who he was.
However, this moment of distraction was enough for Scott to break out of their grip and start attacking Kira and Stiles before setting his sights on Liam, ultimately grabbing him in a choke-hold and pinning him against the wall. Liam, horrified, pleaded with Scott to stop, but his consciousness had been completely overtaken by his transformation into a Berserker. When Scott raised his clawed hand to kill Liam, Liam desperately repeated the same words to Scott that Scott had told him during his first full moon-- "You're not a monster! You're a werewolf-- like me." These words in combination with the connection they shared as an Alpha and his bitten Beta allowed Scott to overcome his Berserker instincts and rip the bear skull off of his head, returning him to the True Alpha that he really is.
Realizing that Peter had orchestrated this entire thing to kill Scott and attempt to take his powers, Scott and Peter began engaging in another fierce one-on-one fight. Scott refused to allow any of the other pack members to help him, but at one point, Liam became so worried for Scott that he instinctively jumped into the fray. In response, Peter picked up a nearby broken church pew and threw it at Liam, who was barely able to duck in time to avoid being hit in the face. Scott, furious that Peter would attack his Beta, used his affection toward Liam and the rest of his pack to give him the strength necessary to defeat the man who made him a werewolf in the first place.
After the battle had ended, Scott, Liam, and the rest of the pack and their allies went outside to discuss what had happened, leading Chris Argent to reveal that he had made a deal with the Calavera Family-- he would help them track down Kate, and in exchange, the Hunters would leave the pack alone and not attack Scott for turning Liam.
Once they all returned to Beacon Hills, Scott, Liam, and Stiles were seen talking to Coach Finstock in the locker room, where Liam was trying to come up with an excuse as to why Scott missed the last lacrosse game, and why Liam, Scott, and Stiles had missed the last practice. Though the Coach didn't believe their excuse whatsoever, he let their absence slide, though he did remind Scott that Liam was the most promising young lacrosse player he had ever seen, and that it was now up to him and Stiles to look after him and have each other's backs. Liam looked over at Scott with a smile, and Scott returned the smile before assuring Coach that they already do.