Pandaemonium

by Christopher Brookmyre.
Unbelievable.
Science meets religion meets teenagers ........ Chaos.
A secret scientific facility under a mountain in Scotland has created an anomaly which has led to demons, complete with horns and forked tails, arriving from a parallel dimension. They are captured and put through all sorts of torturous testing in the facility. The Catholic Church has been called in to deal with these demons and Cardinal Tullian is the man in charge, much to the chagrin and frustration of the scientists.
Meanwhile, a busload of Catholic schoolkids arrives at a school retreat outside, on the mountain. They are there to help them deal with the deaths of two of their school mates.
The first half of the book alternates between these two, apparently seperate, stories. There is a lot of scientific theorising and a lot of theological discussion in the early chapters.
This overt academia is interspersed with chapters detailing the journey, arrival and settling in of the school group. The bus ride to the retreat is just hilarious. There are no long descriptions of these kids but I knew each and everyone of them. Brookmyre has written the dialogue and actions so well - these kids come alive instantly.
Eventually the two stories collide. In a nutshell, the demons escape.
What follows is genuinely horrific but also hilarious in a weird way. The blood and gore and horror just keeps on coming as the kids attempt to save themselves from being torn apart by the rampaging monsters - who are not, in fact, demons, but beings from another world sucked into their own version of Hell.
It's not called Pandaemonium for nothing. I couldn't put this book down.