Way, way, way too long. Barely any story in the 860 pages, it gets some drama around 85% in and holds on for a short while.

It's a shame because the first pages are gripping. Then it's just gripping you for an absolute age and it's just a drag.

Nice idea, stretched beyond a reasonable point. Could have easily been an impressive 300 page book.

But it's not. It's a slog.