Divorced dad and hard-nosed radio talk-doc, Jack Black, takes his kids Ashley and Joshua on a trip to a lake in British Columbia. While Dr. Black works away his vacation, his children learn that the the locals believe they have all been inhabited by Orky, a monster who, legend has it, lives in the lake. Over the course of a few days at the lake, Jack experiences a total turn-around in his ways and discovers the joy of playing with his kids, digging tunnels to China and of turning clouds into pictures in the sky.