(nods) Agreed.

Thinking about this some more, I wonder whether an actual reflection is even necessary.

That is, if one of the four "nutcases" looked into a surface they believed was reflective, but which actually presented an image of a young-looking vampire in Elspeth's memories, would that be enough to trigger the filtering/identification process?

Presumably it would depend on how relevant the body's memories of looking the way it actually looks are to the process. I could see it going either way. Given that the four "nutcases"es original identities are irretrievably lost, and the state of identifying as a single upload seems strictly preferable to the state of being muddled between many of them, it seems like an experiment worth trying.

Unrelatedly: if the uploaded Didyme turns out to satisfy Marcus' mate bond, things just got very interesting. It seems to follow that every vampire in the world who has lost a mate promptly shows up on Elspeth's doorstep, a similar-appearing human in tow, demanding that she "resurrect" their mate. Politically useful, albeit ethically challenging.

The related question of whether Elspeth can "resurrect" humans seems relevant for similar reasons. Available data suggests that she can't, since the vampire memories displace the human ones, but I'd want to see what happens with a blast comprising only human memories. (My expectation would be that it wouldn't eradicate the body's memories in the first place, though... I'd expect the effect to be similar to the effect of Addy's blast on vampires. Still, if the body is already brain-dead for some other reason, that might be different.)

Of course, this isn't just a resurrection trick; it's also a duplication trick. I wonder if any mate-bonded vampires would be interested in a polyamorous relationship with multiple uploaded copies of their mate? (The mate-bond seems to imply monogamous attachment, but that could just be a side-effect of not being attracted to anyone but their mate.) Certainly there are humans who would be.

Unrelatedly: I admire the aplomb with which Didyme and John are handling their physical and cognitive deficiencies. In their position, I would be insisting that someone turn me, right now. (After all, the difference between their current state and the state they remember is overwhelmingly greater than what I experienced when I woke up hemiplegic and brain-damaged after my stroke, and if I could have recovered from that with a few days of agony, I'd have signed up in a heartbeat... even if it was my last.)