George Treet is perfectly happy with his life, being part of a family of travelling actors. The only thing that concerns him are the visits, twice a year, by a dark and sinister stranger.

Then suddenly George's life is turned upside down when Mr Treet tells him that he is not his real son, and that he is, in fact, the son of a wealthy and powerful man. George is sent off to live with his real mother and father and enters a world of dark intrigue and mystery, where someone, somewhere out in the fog, is waiting for him.