Sophie/Promethea have returned from heaven only to be forced into a fight with her friend Stacia/the Grace Branagh Promethea incarnation. After a trial in the Etheria, Sophie goes on the run and refuses to invoke Promethea who will end the the world. Hounded by the FBI and hunted by Tom Strong, Sophie becomes Promethea and ends the world. Of course that isn't the end of the story.
Volume 3 returns to the more accessible narrative of the first volume and is a wild exciting ride which also resolves the fates of the many supporting characters by the penultimate chapter. The last chapter is something else again and has to be seen to be believed. Whatever you may think of it, it's certainly unique.
What is pretty much inarguable is that it's his most beautifully illustrated series and one which places the most demands on the artist; though I'm sure that Linda Gebbie on Lost Girls has her adherents. J. H. Williams 111 (who came to my attention with Chase back in the 90's) does a phenomenal job using a range of artistic and design techniques without ever losing sight of the narrative. On that level alone, I'd argue that it is one of the finest graphic novels ever. One minor but engaging and amusing part is how Williams deliberately copies the style of the artists who drew characters from other ABC titles, often simultaneously in one panel.
I've criticised the lack of extras in previous volumes, particularly the first, but I have no complaints (well, just a couple) about this one. Nothing from Moore but no-one expected that. There are the complete Little Margie in Magic Misty Land (Moore's tribute to Little Nemo In Slumberland) illustrated by Eric Shanower, some Promethea-related bits and pieces from other ABC comics (including an extract, but alas not the complete episode, from Tom Strong's view of the end of the world), Williams writing about visually creating (drawing seems such an inadequate in the context) Promethea, Moore's script for chapter 29, and a half-size replica of the poster version of the final chapter.
And that is it, the conclusion to one of Alan Moore's finest graphic novels. Yes, these three Absolute volumes are expensive but they're worth every penny.