Pippa and Leith, a sister and brother who've been packed off to camp for the summer, haven't even arrived at Camp Damble when things start to go off the rails. After the unstable bus driver finally gets them inside the grounds, they find the counsellors are ruthless and robotic, alternately sappy and sinister. A wild-eyed escapee warns of terrible danger. And what is it that links a black bungalow in the forest to the legend of Headless Henry?

Returning from an uncharacteristically enjoyable day out, they find a fence thrown up around the camp – a fence pulsing with electricity.

Realising that Pippa is next in line "for the treatment", whatever that is, Leith must make his way inside the Black Bungalow, risking his life as he struggles to solve a terrifying puzzle and vanquish a madman. Only if he succeeds will they be free to escape.