Mutation (Wildfire Chronicles Vol. 4) [post-apocalyptic/zombie horror]

The only thing the survivors of the catastrophe in South Wales wanted was a safe place to ride out the apocalypse. The castle looked perfect: high walls and natural defenses that even the infection could not breach. The problem was that someone had beaten them to it. Someone who would stop at nothing to maintain control. Someone with a dark secret that could change everything... Zombie, Horror, Post-apocalyptic, Action, Dystopian, Series, Science Fiction