Abyss - Paul Bryers

Jade is in St Severa's Catholic boarding school in the wilds of Cumbria. She is hiding from her mad-scientist father, Kobal, who is on the run from half the police forces of the world for illegaly experimenting in genetics to create a new breed of perfect human. Jade is part of his personal project, one of his own seven special children born of seven different surrogate mothers. But even St Severa's isn't safe. Driven by his obsession with gathering the children together, Kobal can read Jade's mind. He has five - he needs Jade, and her help to find the seventh.
Only the arrival of Benedict, claiming to be Kobal's brother, saves her from Kobal's clutches. In a race to find the missing seventh child before Kobal does, Benedict sweeps Jade on a fantastic train journey across Europe to the mountainous land of Dracula legend. From the empire of the dead in the Paris catacombs, to a lost Romanian monastery on a remote mountain crag, the final journey takes them to the climax in a ruined castle of Transylvania. And the abyss at its heart.