A new war is starting on “Marvel’s Agents of S.H.I.E.L.D.” Season 2, and it doesn’t involve Hydra. In episode 14, it was revealed that Bobbi (Adrianne Palicki) and Mack (Henry Simmons) were working for an anti-Coulson (Clark Gregg) version of S.H.I.E.L.D. They were planning to take him down in favor of a less secretive S.H.I.E.L.D. According to the synopsis. it seems that Coulson will finally be aware of the secondary organization in episode 15.

“War comes to Coulson’s doorstep in a way he never anticipated as shocking revelations are brought to light,” the synopsis for "One Door Closes" teases. Judging from the promo below, Bobbi is bringing that war to Coulson, and that “shocking revelation” will be her and Mack’s betrayal. Though she convinced her new bosses that she’d be able to keep her cover if she went back to Coulson's team for just a few hours, May (Ming-Na Wen) seems to know that she’s up to something.

Meanwhile, Skye (Chloe Bennet) won’t have an easy time alone in the cabin. She’ll work on containing her powers, but even with Simmon’s (Elizabeth Henstridge) new gloves, she “struggles to control her new abilities,” according to the synopsis. It doesn’t seem like she’ll have much time to focus, though. The promo shows Skye running away. The sudden invasion of the safe house might be what causes her to make “a decision that irrevocably changes her life.”

Watch the promo for “Marvel’s Agents of S.H.I.E.L.D.” Season 2, episode 15 below:

Lucy Lawless will also return in episode 15 as Isabelle Hartley, who died in a car crash in the season premiere. The synopsis doesn’t mention what Isabelle is up to or how she could appear after death.

“Marvel’s Agents of S.H.I.E.L.D.” Season 2, episode 15, titled “One Door Closes,” airs Tuesday, March 31, at 9 p.m. EDT on ABC. Do you think Isabelle is alive? How will she return? Share your theories in the comments section below!