The Flash: Jon Cor Talks Mark's Stunning Choice in "Rogues of War" (Exclusive)

Previously on The Flash, Team Flash and Mark Blaine were hit with some difficult news when the arrival of Khione (Danielle Panabaker) made it clear that both Caitlin Snow and Frost were, in fact, truly gone. It's news that Mark — aka Chillblaine — particularly struggled with as he had been eager to bring Frost back to life. This week's episode, "Rogues of War" saw some of the fallout of his loss — including a surprising betrayal. Now, Jon Cor explains to ComicBook.com what's behind Mark's choices.

Warning: spoilers for this week's episode of The Flash, "Rogues of War", beyond this point.

In the episode, while Barry (Grant Gustin) asks for Mark's help on the Rogue Squad with the goal of stealing a vibration engine before Red Death's rogues can do so and endanger the entire timeline, Mark ultimately betrays the group. It's revealed that Red Death's team approached him just before Barry and offered to help him bring back Frost in exchange for the engine. This ultimately leads Mark to betray Barry and the Rogue Squad — though it also turns out that the Red Death has their own agenda that must be met before Mark will get what he wants. The episode also sees Mark tell Barry that he's agreeing to help Team Flash because he's doing what Frost would — something that seems to take on new meaning once his betrayal is revealed.

"He certainly, when at a loss, and this is what I think is probably most interesting about Mark or what's most fun to play with, is that his love for Frost transcends his moral compass," Cor said. "And I think no matter how, if we dumb it down, so to speak, good or bad, he is at any given moments, his love for Frost, he can use that to justify the means a lot of the time to various ends, whether he knows it or not. Because to him, that is the right thing to do, whether it's good or bad."

He continued, "But again, he's speculating, he's speaking for someone else, he's wounded. Who knows if he's on track or not. And what kind of use or benefit he will be to team Flash or not, being in their orbit or not. And so, we're setting a lot of that up and kicking it off this season."

We also end up seeing Mark having to face the reality of the choice he's made at the end of the episode when Red Death unmasks, revealing someone who looks an awful lot like a sinister version of Batwoman who is uttering "I am vengeance".  Cor said it's definitely a moment that destabilizes Mark, at least in the moment.

"A lot of things are going through his head. But when it comes to this transcendental love for Frost that he uses to drive most of the decisions he makes that are significant in his superhero world, shall we say," he said.  "Yeah, I think he definitely feels as though he is in over his head in that he's burnt virtually every bridge he's had left probably. Or at least the risk of him burning those bridges is certainly there. He seems willing to do so.

And this new one that he's built, I guess is suddenly something that I think he realizes is so much greater and more powerful than he is. That perhaps whatever he wants or needs or whatever he thinks he is worth perhaps to this other person in terms of what he has bargain with, suddenly seems fairly small, I think."

He added, "He goes from maybe feeling pretty checkmate, finally. No matter what, I'm going to restore the love of my life and live happily ever after. That immediately turns into, I was holding the key maybe, but now I'm holding a bomb. And yeah, I don't think he wasn't prepared for that twist."

The Flash airs Wednesdays at 8/7c on The CW.