None of this is a clear answer, but it does provide hints, things to grab and hold intrigue without giving too much away. James can recognize the tactic as one he uses himself, though in a very different manner, and likely for different motivations; still, although he's aware of the strategy and of Zane's studying of him, he can't help but be drawn in. Is this Dark Presence real, or metaphorical? Had it only pretended to be Barbara, or had Barbara herself been truly brought back, but affected by something other than herself? Had cutting out her heart and drowning them both been literal, something he would've never really contemplated as possible before awakening here, but now knows could very well have occurred?

And then Zane makes those last few comment, and James is not amused with the insinuation that perhaps this had all been just a story. He doubts it was, and thinks this is either a last moment attempt by Zane to play off being too honest about the subject, or that he's just purposefully messing with James, or both. Whatever the case might be, he dislikes the purposeful attempt at creating ambiguity, and although his tone is lightly neutral when he responds he matches the flippancy through his words.

"This may be an appropriate time to admit that I don't know what a movie is."