Minor complaint: the episode description says "Holden sees past, present, and future" - it is a good thing that they flat-out told us that, because I still have no idea what Holden was seeing. The little blue planetoid/ship, yes, 6 (or 8, I forget) other worlds, going blue (protomolecule?) and a close-up of one of them in flames.
Someone upthread mentioned Amos talking about what happened to him when he was 5 - didn't we already get hints about that, way back when he was talking to one of the Evil Scientists (the one Dawes has now) about pretty much having part of his brain removed/killed/seriously altered, and he was asking the scientist (in a round about way) if that could be reversed? That's what I assumed, anyway, that was the reason that little tidbit was there. Not sure why anyone would do that to a 5 yr old on purpose but it might have been part of some other issue.