David Norton is a professor at the Faculty of Experimental Psychology at Helmstone University. One night, he rescues a drowning swimmer off Helmstone Pier. She is Mary Costelloe, a beautiful woman with a past that does not add up and a present that quickly gets tangled with Norton's - until one night he finds her gone.
Two years later, Norton receives an astonishing letter. Mary has inherited Malpas, a vast, crumbling Georgian house on one of Ireland's great rivers. She is the owner of thousands of acres of tangled forest, two ruined abbeys, a derelict private gasworks, a full-scale replica of the Grand National course. Malpas, its estate and its inhabitants are a world of their own. A beautiful world. But a world with chilling secrets, where madness stalks the riverside oak-woods.
Mary's new husband has drowned himself in the river - the latest in a string of bizarre suicides stretching back eighty years. Darkness is rising around her. She needs company. More than that, she needs help. David Norton has rescued Mary once. As he begins to delve into Malpas's tormented past, he begins to realise that this time it may not be so easy. And that he is in danger too . . .
