Sally Green's second book Half Wild isn't Half Bad (In fact, it's excellent!)

In an alternative England, where black witches and white witches live amongst ordinary humans, teenager Nathan Byrn is an outcast. He is a "half-code", the child of a White Witch mum and Black Witch dad.

As Nathan grows up, everything is done to keep him on the white side. He is regularly assessed to ensure he is not slipping into the black side. Everyone around him watches for the slightest slip-up or mistake, expecting him to turn out bad like his dad.

Sally Green's Half Bad was one of the top bestselling YA novels of 2014. And deservedly so. In Nathan, the author introduced a strong new central character, and his story was fresh, edge-of-the seat stuff.

Half Wild picks up where Half Bad left off, and Green, much to her credit, doesn't waste time recapping the first book but dives straight into Nathan's continuing story as he fights opposing factions to become the person he wants to be. The only downside is that, if you haven't read the first instalment, you might be a bit lost; that's yet another reason to grab a copy of Half Bad, though.

Nathan has received his magical Gift, which witches get when they turn 17. But the all-powerful Council of White Witches sees him as a danger, and its leader, Soul O'Brien wants Nathan out of the way, so Nathan is on the run.

O'Brien wants to rid not just England, but all of Europe of black witches; but in a surprising turn of events, an alliance has sprung up between a small group of black and white witches who want to destroy O'Brien. Drawn into the fight for power, Nathan finds himself fighting alongside and against old and new friends and enemies.

But why should anyone trust a "half-code", whose allegiances are surely split between good and bad?

Light and dark, good and evil are in continuous flux in Nathan's world. The plot and characters in this second Half outing are just as strong as in the first, with many characters from Bad appearing, and new motives, new alliances and new enemies piling up.

Nathan's father, Marcus, is an ominous and enigmatic presence Nathan can neither trust nor dismiss. The young white witch Annalise, with whom Nathan has fallen in love, has been taken prisoner, adding more complications for our hero to sort out.

Get up to speed with Nathan's story before part three hits bookshops next spring.

John Millen can be contacted on [email protected]