It's left deliberately ambiguous, so it can be whoever you want. I am a huge fan of deliberate ambiguity. See also: After the Final Moment.

And as for where I'll take it...well, nowhere. This is what is generally known as a one-shot. Multi-chapter fics are actually a rare occurance for me; generally my ideas can only sustain themselves for a few thousand words, and my writing style is far more suited to self-contained stories.