In the season premiere, a new Alpha Pack arrives to wreak havoc on Scott's life while Derek and Isaac struggle to locate Erica and Boyd.

Allison and Lydia stumble upon a possible clue to finding Boyd and Erica while a childhood friend of Stiles goes missing.

With Boyd and Cora on the loose and under the influence of the full moon, Scott and Derek must turn to an unlikely ally for help.

While Scott tries to keep Isaac from engaging in a deadly confrontation with the Twins in school, Stiles attempts to prove his theory that the killings have nothing to do with werewolves.

During a bus ride to a cross country meet, Scott and his friends flash back to the events of a preemptive strike against the Alphas that has left several injured and possibly one or more dead.

Stranded at a motel for the night because of the postponed cross country meet, Scott and the others suffer strange experiences that cause them to believe members of their own group may be the mysterious killer's newest targets.

As the danger begins to reach closer to Scott, threatening his trusted mentor and boss, Deaton, Kali and the Twins go after Derek.

Seeking answers, Scott, Allison and Stiles hear stories told by two unlikely narrators and discover a secret about the color of a werewolf's eyes.

As Allison begins to suspect someone dangerously close to her may be involved in the murders, Scott and Stiles conclude that Lydia's rising talents may be their best bet to solving the murders.

Trapped inside an evacuated Beacon Hills hospital by a powerful storm, Scott and Derek must defend themselves against the Alphas while trying to figure out how to save Cora's life.

Under Deaton's advice, Scott and his friends use an ancient but extremely dangerous ritual to help them both save the lives of the people they love and stop Deucalion from achieving his sinister goal.

After a near death experience from the Nemeton Scott, Stiles and Alison start hallucinating and a dark curse is left upon which makes their life hell.

Scott and his friends race to figure out how to catch the Werecoyote before it's hunted down while Derek and Peter are broken out of captivity by an unlikely ally.

The twins are back in high school and look to join Scott's pack while a killer escapes from hospital for his next target in high school.

Beacon Hills is under curfew from the power outage; the teens throw a blacklight Halloween party; Scott tries to earn Kira's trust.

The gang finally figures out who or what is behind the mask.

Stiles is kidnapped and the pack search for him.

Stiles is back and Scott must prevent a disaster; Lydia and Allison seek help from an unlikely source.

Stiles is put into a mental hospital where he believes he will be safe from the Nogitsune. Will he be as far away from it as he thinks or closer than ever? Meanwhile Scott, Allison and Lydia look for a cure for Stiles.

With the Nogitsune still in control of their friend, Scott and Lydia find an unlikely ally in Peter Hale. Elsewhere, the effects of the Nogitsune have given Chris, Alison and Kira some trouble with four out-of-control werewolves.

Scott and company race to rescue Lydia from the clutches of evil as the Nogitsune makes a surprise move, resulting in a tragic loss to the group.

Struck by disaster and nearly defeated, Scott and Derek call on their friends and allies to make one last stand.