Stiles Stilinski has set up an intense case of friend vs. foe on Teen Wolf, and his life may very well hang in the balance.

As Scott's (Tyler Posey) pack works to save the sarcastic teen from the Nogitsune that is possessing him, Derek (Tyler Hoechlin) will be carefully weighing the cost of saving Stiles (Dylan O'Brien).

"It's an intense conflict. That's something we all have to deal with for the rest of the season is the idea of, 'What are we attacking and what are we saving?' Are we saving a friend or a monster?" Hoechlin told Just Jared Jr. "Do you kill someone you care about to save many, or do you try to save everyone and possibly fail miserably? That's going to be the conflict for a lot of people."

Just as Stiles often joked about offing Derek in season 1, the former Alpha would have given little thought to dispatching Scott's pal in the early days of the series. Now, however, Derek's mindset is slightly different.

"You'll probably see a lot more concern from Derek than you would have in the first two or three seasons where he would have been like, 'Just kill him...because I don't like him anyway...and it's an easy reason to get him out of here.'" Hoechlin explained to Just Jared Jr. "I think you'll actually see a little bit more concern and care from Derek."

Teen Wolf airs Mondays at 10 p.m. ET on MTV. Click the video below for a preview of next week's "Letharia Vulpina."