The secret behind Derek's tattoo is revealed and the Alpha pack make their presence known. Derek and Isaac struggle to locate Erica and Boyd.

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 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.

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.

Gerard initiates his final attack on the Supernaturals of Beacon Hills