Bantock has a wonderful style, and this book may be my favorite among the ones I've seen.
Like the Griffin and Sabine books, it has a definitely mystical side. As the name says, it's about purgatory, but not Dante's. This is a place where people have work to do, and our protagonist works as a museum keeper. That sets the scene for a series of peculiar vignettes, the kind that make just a little too much sense.
Also like G&S, there's a distinctly autobiographical sense about the story. The last section is explicitly a fictional autobiography. Somehow, though, the stories have a grounded feeling that doesn't let me believe they are pure fantasy.
As much as I like the G&S imagery, I like this better. Bantock has moved his improbable talent for assemblage and collage into 3D. He has created several series of fictional artifacts, are as complex and multifacted as his works on paper. These images, so many being photos, have a clarity that G&S sometimes lost.
This is a brief but very enjoyable book, and one worth re-reading. The pictures just get better with each reading, and the stories seem to stay fresh.