Clarke is forced to seek the help of an old enemy in "The 100" season 3, episode 15, "Perverse Instantiation – Part One." Clarke has run out of options as they attempt to take down Alie, pushing her to turn to Roan.

Clarke knows that this battle is bigger than her and Roan's rivalry and that their hostility towards each other won't do any good because the real enemy is not each other but a much greater force. Roan seems to agree with Clarke.

"The enemy we're up against is after everyone," Clarke tells Roan in the "The 100" season 3, episode 15 promo. "Like it or not, we need each other," she continued, successfully convincing her nemesis.

While Roan and Clarke have found middle ground, Bellamy can't help but think that this newfound, not to mention unlikely, alliance is a bad idea, especially because of the fact that Clarke is entrusting her life to someone who has gone to great lengths just to get her killed.

Clarke has already shown that she is prepared to do everything to save her people, and if it takes placing her trust on someone that can destroy it without a second thought, she would do it. There's also the harsh reality that she has no other choice.

The CW is keeping details about "The 100" season 3, episode 15 a secret, however, the network did hint that Alie's endgame is coming to fruition and that Clarke is hopeful of how things will turn out with her new ally.

Still, there are some fears that even Roan might be chipped and actually under Alie's control. If that is the case, Clarke will be in big trouble.

"The 100" season 3, episode 15 teaser also gives fans a reason to fear for Clarke's safety. In the clip, Bellamy notices "something's wrong" as he looks through his sniper gun. He turns out to be right because after he said that, an explosion occurred. Has Clarke made the wrong call about Roan? Has he really turned into a friend or is he still a foe?

"The 100" season 3, episode 15 "Perverse Instantiation – Part One" will air on May 12 at 9 p.m. ET on The CW.