Tyler Hoechlin, Colton Haynes and Tyler Posey tell THR what to expect from Monday's season two ender.

An incredibly dark storyline is about to get even darker when Teen Wolf finishes out its second season on Monday, with MTV promos posing the question: who lives and who dies?

The actors behind Derek (Tyler Hocehlin), Jackson (Colton Haynes) and Scott (Tyler Posey) stopped by The Hollywood Reporter's cover lounge to discuss the finale, revealing that they don't even know how it ends.

"This year we have multiple endings, so I will find out, along with everybody else who watches on Monday night, which way it goes," Hochelin says.

"There's a big death at the end that they're teasing right now and you don't know who it is," says Haynes. "It could be any one of us."

Pressed to reveal something that fans will see on Monday, Posey reveals that "there will be black blood oozing from someone's eyes and ears -- and every orifice imaginable." Sounds familiar. Jackson fell prey to the same ailments earlier this season just before transforming into the Kanima. Hmm…

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The guys also reveal that Lydia (Holland Roden) will be coming back into the action in a big way this week.

"She possesses something that could help all of us at Beacon Hills -- or possibly harm us," says Haynes.

Adds Hoechlin, "Lydia's been very important to the show, especially this season. The way that the show ends up, she'll kind of be putting a nice little end cap on that for the season."

Watch the video above for more from the guys, including what to expect from Scott's family relationship (now that his mom has been clued in to his little secret) and whether he can ever have a future with Alison (Crystal Reed).

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The Teen Wolf season two finale airs Monday at 10 p.m. on MTV. If you missed any of the action leading up, the network will air the previous two episodes just before the finale, beginning at 8 p.m.

Click back to The Live Feed on Tuesday for more from Hochelin, Haynes and Posey about what they're looking forward to from the super-sized season three, expected to begin shooting later this fall.

Email: Sophie.Schillaci@thr.com; Twitter: @SophieSchillaci