It's a crazy story, of course, with supernatural elements juxtaposed with the more usual Brookmyre fare of stroppy Glasgow kids and a challenging environment, in this case somewhere beyond Inveraray. There's a horrific incident involving a burning bus, a crash, and a deer on the roof - but that's just to introduce the various kids as they head for a weekend of bonding and debriefing after a fatal stabbing in their school. The real horror comes from a parallel tale of an underground facility and a top-secret military experiment, long since out of control - and in the same area as the base for the bonding weekend.
The language is foul, the descriptions gory, and the discussions among the staff about the nature of belief surprisingly serious and interesting. The tension builds beautifully - perhaps hideously might be a better word - and the climax is unexpected. I didn't expect it anyway. I just enjoyed it.
At this rate I'll never read a serious book again.