B Smith has found a home; a leader with a mission from God; A mentor to teach her kick-ass fighting skills. And allies just like her, revitaliseds, zombies with a mind and conscience.

Or has she? If the ZOM-B saga has an over-arching message, it is, find your own way. Do the math. Do the spade-work. Get your hands dirty. In other words, don’t accept answers, or a world-view, on a plate. Test-out. Think. Work it out. If you arrive at a philosophy or faith or political side or world view by your own thinking, by your own testing with mind and heart, well then, you have been true to yourself, and your beliefs should serve you well. Accept on face value the sales patter of another, however, and then you risk integrity, and more.

This message started with the principled teacher Burke in ZOM-B as he challenges B’s racism. It is developed further here, as B wonders whether Doctor Oystein is madman or Prophet. He claims to know the origin of the zombie plague and be on a mission from God to help eradicate it, against the satanic incarnation of the Hellish clown Mr Dowling and his hoodie mutants. B would like to believe him, but Burke’s words, and lessons from her own past, make her leave the Doctor’s safe refuge and strike out again across Zombie infested London. Can she trust what she has been told? B needs to see more of what is out there, and test it out. She will meet old friends; meet new ones, and the titular un-dead baby, who does not in fact make an appearance until the closing chapters of the book.

In this instalment there’s a big focus on religion, or faith. Doctor Oystein has it. Timothy the mad artist has it. B is not sure. She listens, but needs to think it out for herself, test it out in the crucible of a Hellish apocalypse. No answers are served for us in a plate. There’s an ambiguity to it all that keeps you hooked, and is in keeping with the theme of thinking it out for yourself.

As usual the writing is brisk and effective. There are some great set pieces. A race up the London eye, the appearance of the ZOM-B Baby, an attack on an art gallery; these are held in a swell paced narrative that uses its 12 book story arc to maximum effect. You can slowly deepen some mysteries whilst rapidly progressing others.

I don’t know which side the writer will land. I hope he doesn’t, and manages to sustain this tension. This is good, intelligent stuff, all the better for not flying a particular flag. Shan resists the temptation to go all Dawkins or all St Paul on us. His end message, conveyed so well to us by his be-clawed and be-fanged un-dead is, do your own homework.