We finally get to see Stiles get some action — but then his paramour goes missing. No, not Derek. Heather, a girl he used to take baths with.

Still sporting their bruises from the biker chick, Lydia and Allison decide to ask Scott about their oddly shaped contusions in Teen Wolf Season 3, Episode 2, “Chaos Rising.” However, Stiles and Scott are too busy having a Lydia/Allison-free night by heading to a party at Heather’s — aka, Stiles’s former bathing buddy — house.

At the birthday bash, Heather has her sights set on Stiles. She takes him to the basement to ostensibly get wine so they can drink it out of Solo cups. Instead they start making out. Scott takes the opportunity to answer Allison’s call.

Although Heather is ready to lose her virginity, she didn’t come to the basement/wine cellar prepared with protection. Stiles heads upstairs so they can practice safe sex.

Allison and Lydia arrive at Heather’s house to show off their bruises to Scott.

Bottles start dropping around Heather in her wine cellar/basement. Barefoot, she doesn’t attempt to do her best John McClane and walk on broken glass. Instead, an unseen entity pulls her out the window.

Stiles comes down to find the wasted vintages. In a messed up version Cinderella, all that’s left of Heather is her shoe.

Despite Isaac’s trepidation, Peter Hale performs an ancient ritual — used mostly by Alphas — on the younger werewolf. By digging his claws into Isaac, Peter can access his memories. He sees shadowy glimpses of Boyd and Erica. He hears Deucalion promise that by the next full moon, tomorrow, they’ll both be dead.

In one of the tensest clubhouse meetings ever, Derek rolls his eyes at Allison’s and Lydia’s bruises. Ever since Derek killed Allison’s mother, they just haven’t gotten along. He accuses her of seeing patterns that aren’t there. Lydia has a word for that: apophenia.

Back at school, Stiles and Scott wonder what a pack of Alphas would want with Erica and Boyd. Scott gets some weird sort of tunnel vision when he passes the twins, and it’s probably not because he finds them as attractive as Lydia does. (Note: Based on Lydia’s gaydar, only one of the hot twins is straight.)

Coach is as shocked as we are when Scott knows the answer to a question about risk and reward in regards to the stock market. When the Sheriff pulls Stiles out of class, we learn why he hasn’t been concerned about Heather. He assumed she ditched their sex session. His father tells him the truth: No one has seen her since the night of her party.  

Things get very Fringe when the vet decides to access Isaac’s lost memories of Boyd and Erica’s whereabouts by placing the werewolf in a trance-like state by nearly killing him with an ice bath. Derek and Scott dunk him in the water and hold him down. Didn’t a similar drowning scene make someone turn murdery last season? For someone who’s mostly dead, Isaac is very chatty and tells them Boyd and Erica are being held in an abandoned bank vault — only the female werewolf is dead. Derek hopes this isn’t the case. Aw. Alpha feels.

The gang decides to plan a werewolf heist from said vault, but Allison is way ahead of them. She figures out her bruise is one half of the closed bank’s logo and heads there to check it out. As she wanders the dark bank alone, we have to wonder where her hunter’s tools are, or at least a flashlight.

Someone grabs Allison. Gasp! It’s Ms. Morrell, guidance counselor extraordinaire. Allison has detention for skipping school. Just kidding. Ms. Morrell sends Allison to the storage room and tells her to wait until the fighting starts. There Allison sees Erica, who doesn’t look very alive.  

Stiles’s nerves are wracked. He and Peter try to puzzle out why the Alphas waited so long to kill Boyd and Erica.

Miles away, Scott suddenly starts to wonder the same thing as he and Derek are about to break into the bank. He starts babbling about what Coach said about risk and reward. Derek shushes him because he has a pack to look after and heads into the vault.

After Derek punches through the wall (BAMF), Scott gets a call from Stiles. The Alphas have been starving the werewolves of moonlight, meaning their transition tonight will make them extra powerful. “They’re the starved lions, and you and Derek just stepped into the coliseum,” Peter tells them over the phone.

It turns out Boyd wasn’t just holding the hand of Erica’s rotting corpse. The female werewolf he’s been talking to in Isaac’s memories is Cora, Derek’s sister. No one’s more surprised than the Alpha, who thought his sibling was dead. After Allison lets Boyd and Cora escape in order to save the would-be rescuers’ lives, Derek finally loses it on her, hinting that her mother was less than perfect. Then he tells Scott to finish the story.  

Meanwhile, Lydia screams in her bed.

Next week, in a scene that’s so last season, Papa Argent pulls his gun on Scott.