Scott, Stiles, Kira, Lydia and Malia traveled down to Mexico in an effort to find Derek in Teen Wolf’s forth season premiere, “The Dark Moon.”

Scott And His Pack Are Captured By Calaveras

Stiles (Dylan O’Brien) and Lydia (Holland Roden) enter into a secret nightclub in Mexico and arrange a meeting with the Calaveras matriarch – the huntress who captured Derek (Tyler Hoechlin) and Peter (Ian Bohen) in season 3. Lydia and Stiles put $50,000 on the table and offer it in exchange for Derek. Ms. Calaveras is not impressed, and she tells the two high-schoolers that they should not have come alone, to which Stiles responds, “What makes you think we came alone?”

Kira (Arden Cho), Malia (Shelley Hennig) and Scott (Tyler Posey) are all dancing in the club upstairs, listening in and waiting for their cue. Guards start to search for them in the club, and Scott gets to work eliminating them one by one as a negotiating tactic while Malia and Kira “blend in” by dancing with each other and attracting a large group of men around them.

Calaveras has had enough and she gases the club with Wolfsbane, weakening Scott and Malia enough to be captured. She sticks Malia, Scott, Stiles and Kira in a locked basement and takes Lydia out to tea to test her Banchee abilities. She wants to know how Lydia has harnessed her power and how it works, but Lydia herself doesn’t know. However, it seems clear that it has something to do with sound waves, as the rhythm of Calaveras tapping on her knife suddenly makes Lydia realize that Calaveras is about to kill one of her goons. Back in the dungeon, Malia is wondering why they don’t just attack whoever opens the door next and run, leaving Lydia behind. She’s still learning how to be human after all those years spent as a coyote, apparently: “ Stiles reminds her what they talked about: they don’t leave anyone in the pack behind, or “Rules of the wild kingdom don’t apply to friends.”

Scott Realizes Kate Is Alive

Determined to test what kind of alpha Scott is, Calaveras takes Scott, Kira and Lydia upstairs to her torture chamber and leaves Stiles and Malia locked downstairs. Kira is forced to administer electric shocks to Scott while Calaveras questions him. If she refuses, then one of the Calaveras goons will shock Lydia, who, as a Banchee, has no healing powers. Scott takes the hit, and is almost killed by the shocks until it jogs his memory and he realizes that Kate Argent (Jill Wagner) could still be alive. Meanwhile, downstairs, Malia, who is also learning how to harness her abilities, is able to focus her coyote powers by focusing and clearing her head with a kiss from Stiles.

Satisfied that Scott will now be able to track down shewolf Kate and Derek for her, Calaveras lets the group go. She even sends them off with a guide, the mercenary Braeden (Meagan Tandy), who saved Isaac in season 3. But, before she bids the team farewell, she warns Scott that, for now, they may be on the same side, but the second he bites an innocent and turns someone into a wolf, she will hunt him down.

The group piles into Stiles’ trusty Jeep and follow Braeden up a dirt road to La Iglesia, where Calaveras believes Kate has been hiding out. On the drive, Scott, Stiles and Lydia tell Malia and Kira about Kate, identifying her as Alison’s (RIP) aunt and “a total sociopath.” Scott recounts what he gathered from the Calaveras: Peter scratched Kate deep enough to turn her, and the Calaveras, knowing this was a possibility, smuggled Kate’s body out of the morgue as it slowly healed. For a hunter to shift into a wolf, they must take their own life, so the Calaveras locked Kate up and gave her a blade. She turned and ran away, killing half a dozen people. Then, she supposedly went to kidnap Derek and is holding him hostage in La Iglesia.

Mysterious Creature Attacks Stiles, Lydia, Kira, Malia

Something hits the Jeep, and they are forced to stop, but Braeden wants them to keep going. It’s not safe at night, she says, so they need to reach La Iglesia before sunset. Scott hops on the back of Braeden’s motorcycle after an awkward hug goodbye with Kira while Malia, Kira, Lydia and Stiles work on the Jeep. Malia finds a large horn-like spike – which looks like it’s ivory, bone or a large fang – crammed in the wheel of the Jeep. Later, after the sun sets, Malia thinks she feels something watching them and Kira takes out her sword and uses her foxfire power to illuminate something in the distance. She spots a large, shadowy, animal-like figure in the distance, and Malia just roars and takes off after it. Kira runs after her, and Stiles desperately wants to follow, but Lydia reminds him to focus on fixing the Jeep. Kira catches up to Malia, but whatever was there is now gone and Malia didn’t get a good look at it, but, she says, “It’s big and fast, and it cuts deep.” She has a huge gash on her side to prove it. The girls walk back to the Jeep, which is now, thankfully, running. As they continue towards La Iglesia to meet up with Scott, a frantic Stiles pleads with Malia to never run off like that again. He thought she ran off for good, that she was abandoning them, but she tells him that she would never leave him. Kira and Lydia, sure, but she would never abandon Stiles. Kira smiles in the backseat and Lydia rolls her eyes before commenting on Malia’s injury. Malia insists that she can feel her cut healing and informs them that whatever attacked her smelled like death.

Scott And Braeden Rescue Derek

Scott and Braeden arrive at La Iglesia: ruins of an old Aztec temple dedicated to were-jaguars, the Nagual. They enter slowly, descending into underground tunnels, armed only with Scott’s Alpha and a huge shotgun. The tunnels are dark and creepy, and it doesn’t take long before they are attacked by some mysterious, skeletal creature. Braeden uses her gun to try to fight it off, but it doesn’t work, so Scott unleashes his Alpha roar, scaring it off. They continue and find a stone wall with a Jaguar god engraved on it. Scott breaks through the wall, and Derek's hand reaches out to him.

When Stiles and the gang finally reach La Iglesia, Scott and Braeden are exiting, with a 15-year-old Derek (Ian Nelson) in tow! (Fans will recognize this young Derek from a flashback episode in season 3.) Yep, after being stuffed behind a wall in the temple, it appears that Derek has aged backwards somehow.

Teen Wolf airs Mondays at 10 p.m. on MTV.