“A Hen in the Wolf House” is episode five of season two of Marvel’s Agents of S.H.I.E.L.D.
At the end of the previous episode, “Face My Enemy”, Raina was told by Daniel Whitehall to return the Obelisk that she took in “Heavy is the Head”. An attack on a naval anti-HYDRA unit kills a lot of people in a similar manner to how the Obelisk does, leading S.H.I.E.L.D. to believe that HYDRA has the Obelisk again.
They don’t, though. Skye’s father has it, and he refuses to give it back. He’s not exactly the most stable of individuals. Desperate to preserve her life, Raina tells Coulson that unless he turns Skye over to her, and lets her take Skye to her father, she will expose the fact that Simmons is a S.H.I.E.L.D. agent to HYDRA.
Coulson also informs Skye that it’s possible that she’s an alien. She takes it well. Sort of. Well, maybe not.