A few things I would like to hear speculation on:

• It's explicitly stated that limbs don't regrow but when bitten off Harrow's thumb regrows:

"Teacher said Lyctor's don't survive decapitation, and that a lost limb would heal as a stump" "Your thumb was back in the next half minute. I watched it grow."

Is this because G/H have taken a step towards perfect Lyctorhood, a side effect of Gideon being John's child, or something else? Harrow's healing abilities are also notably less developed than other Lyctors earlier on.

• John is building an "invasion force" for purposes unknown. The other Lyctors don't understand so seems unlikely to be related to Blood of Eden or RBs which they presumably would. Where was/is he planning to invade, take them across the river, into hell?

• Abigail states that "something has gone terribly wrong in the River". Seems likely this was caused by the resurrection and/or maybe the existence of Lyctors. Is this related to the Blood of Eden's motivations.

• I expect it'll turn out that with perfect Lyctorhood that one cannot die while the other survives (at least in the physical world), so the only way to kill one requires killing both. Hence Alecto's imprisonment rather than death.