Peggy Carter has a very big decision to make in the season finale ofMarvels Agent Carter.
At this point, you realize the extent of Whitneys abuse of power, Atwell tells EW.
I think shes kind of an addict, and Zero Matter is her drug of choice.

Credit: Kelsey McNeal/ABC
Whitney is someone who is very dangerous, Atwell continues.
Shes a psychopath, even to the point where her own people have turned against her.
Its quite scary for Peggy to make a run at work out.
Unfortunately, it happens that Whitneys used her brain for the force of evil.
Its Peggys self-fulfilling prophecy, I guess.
Its a real struggle for her because she really wants to love, Atwell says.
I could end up harming them even more and end up alone again.
I think the whole thing is quite difficult and dangerous for her emotionally.
The season finale ofMarvels Agent Carterairs Tuesday at 9 p.m.