There's nothing in a glorious summer's day to suggest anything even remotely sinister. In fact, Alex Callahan, a news correspondent, surprises himself by enjoying the Renaissance Faire that his six-year-old twins, Kevin and Sean, have forced him to visit.

The boys are delighted by the jugglers and magicians, jesters and foodmongers dressed in full Elizabethan costume. But it's the joust that the boys have really been waiting to see. Alex takes a break to watch, while keeping half an eye on the twins, but when he turns to see how they are enjoying themselves, they're nowhere to be seen.

The perfect day has turned into every parent's nightmare. His sons have disappeared, and Alex is an immediate suspect. But no one can explain the bizarre origami figure he finds after he returns to his empty house. Or the bowl of water that has been left on the top shelf of the wardrobe. Or, the T-shirt soaked in blood...

As police attention to the case wanes, Alex's own investigations uncover a sinister, underground world that he never dreamed existed. A world where reality is portrayed as illusion, and where the reason behind the twins' disappearance is more terrifying than anything Alex can imagine...