When Clarke is taken by grounders, she's oddly effected with a mixture of sadness and fury when she finds out that Bellamy didn't go after her. (Bellamy/Clarke pairing of course, set after 1x11)

Bellamy and Clarke begin having strange dreams about each other, only they're definitely not the same kind of dreams. This, coupled with a new killer in camp, puts them both on edge, and brings them closer together.