Lexa and Clarke team up against a new bad guy in The 100 season 2, episode 10, “Survival of the Fittest.”

Last week on The 100, Lexa introduced Clarke to her philosophy: love is weakness.

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As the Grounders and Sky People came together to burn Finn’s body (along with the 18 people he killed), Lexa’s right-hand man Gustus tried to break up the alliance, but that only resulted in his death.

Now, Clarke and Lexa must work together to free their people from Mount Weather – but not before fighting off a new enemy, which leaves them terrified (judging by the promotional images).

Related: The 100 introduces its first queer character: Let’s discuss!

The remaining Grounders are led into Camp Jaha, where they are introduced to guns… with predictably disastrous results.

Meanwhile Jaha and Murphy head to the dropship to visit Wells’ grave, while Bellamy and Lincoln must set their differences aside in order to infiltrate Mount Weather.

A sneak peek from the latter storyline has been released, in which Lincoln tells Bellamy about the Cerberus project:

In the clip Lincoln interestingly reveals that when he was a boy, he saw a ship fall from the sky. This is the first we’ve heard of any other exodus from the Ark, and while Bellamy writes it off as a “suicide by Earth,” we have to wonder if there could be more tribes of Sky People out there somewhere.

There’s also a nice line in the clip, where Bellamy tells Lincoln he made Octavia strong, and Lincoln replies, “She was already strong.” +1 for Linctavia.

‘The 100’ season 2, episode 10 airs tonight at 9/8c on The CW!