This book caps the Weatherlight saga in terrific style, and is easily the best of the three Invasion installments. The ending is definitely as big as could be imagined; one of the most apocalyptic apocalypses you're ever likely to see. A word of warning though, you might want to have read "The Thran" or a number of references might be lost on you.
King has managed to live up to the hype generated by the other two books. The story focusses on Gerrard's experiences inside the Stronghold and the Phyrexian Arena, and also on the final desperate attempts by the armies to penetrate the Stronghold's volcano. Meanwhile the remaining planeswalkers continue Urza's plans despite his absence.
King has decided to include a healthy ammount of humour in this final book, which was notably absent from Invasion and Planeshift. Squee is great as he gives Ertai a really horrible time. Commodore Guff, the other comedy relief, is hilarious, and the Wild Research scene is so audacious you'll be amazed that King managed not to mess it up somehow.
While it's plainly obvious that Yawgmoth is probably not going to win, King pushes it so close that you're going to be wondering right up to the end. The fight against Yawgmoth himself is rather confusing, though, as the author seems to test out a few possible endings then grow bored with them, and pulls the Weatherlight back to try something else. Despite that minor problem, which might not even be a problem as it keeps the reader on edge, and the omiting of a number of Legendary cards (well, maybe it's just me who keeps a mental checklist when I'm reading the books), this was a fantastic read and well worth it. Let's hope Odyssey is as good as this.