B Smith has finally fully committed to the Angels, a group of conscious zombies led by Dr Oystein. B has worked through some of her issues about friendship and attachment in this post-apocalyptic world and is beginning to forge genuine friendships with her fellow revitalised. She's even getting on ok with her nemesis, Rage. And both B and Rage are ecstatic when Dr Oystein finally sends them on a mission.

They are to take Emma and Declan, humans they rescued in a previous book in the series, to a commune outside London. It's a perilous journey and - as you'd expect! - there will be casualties along the way. B meets up with both an old friend and an old enemy and the reader gets to see a picture of the world outside London that the series hasn't shown them yet. I liked this aspect of Mission - I felt as though the series was properly advancing, something I've criticised slightly in other books.

Mission also reintroduces racism as a theme. This was important in the first book and it's been talked about since but it hasn't really been front and centre as it is here. I don't think I'm giving too much away if I say that the nasty of nasties Owl Man is caught up in all this. Zombie stories can be read as allegories of racism - how we hate and distrust the other - and I like the way Darren Shan is making us think about it in ZOM-B - humans distrust the revitalised and many of them still can't let go of a skin colour prejudice. And in this devastated world, it's easy to incite hate.

ZOM-B Mission is fast and furious and gory and great fun. Of course, it also ends on a blasted cliffhanger but I've given up moaning about that. I loved it.