Previously, Scott accidentally bit Liam in order to save him. In a panic, Scott kidnapped him and called Stiles to help.
The two boys try and fail many times with different approaches to explain to Liam about the bite. #TheBiteIsAGift
Peter gets hit by the mouthless guy. The guy informs Peter that Derek is next
Lydia looks through her math notes and find a weird code. Kira tells Lydia "you hold the key"
As a final hail Mary, the group get Kira to seduce Liam into going to Lydia's boathouse for an intervention of sorts. They tell Liam what they all are: Scott - werewolf, Lydia - banshee, Malia - werecoyote , Kira - "fox" aka kitsune, and Stiles - used-to-be-possessed-by-an-evil-spirit. #VeryEvil
Liam texted a bunch of his freshmen friends before going into the house so they all showed up right when Liam was about to turn. (It's a full moon. Coincidence? I think not!)
Stiles and Malia go into the basement. They have a bonding moment, she learns to use Stiles as her anchor.
Scott and Kira take Liam into the little shed by the water. They have a bonding moment, they slow dance and Kira tries to get Scott to lose control. But he tells her he is "undistractable." Liam turns, breaks out of his chains, and run into the forest.
Allison's dad, Sr Argent save Scott right in the nick of time. "How did you know?" "I got your text." (I'm assuming the tex was from one of the previous episodes and he finally decided to show up.)
Lydia cracks the code and types in "Allison" as the password. A list with a bunch of names and numbers next to them show up on the page. She calls it a 'deadpool.' (I'm assuming they're just bounties or a very real game of assassins)