Twelve year-old Martin Jessup, teler of all tales and other untruths, cannot understand his sister's objections to their family's move from Winnipeg to small-town Ontario. With dad in the military, moving is a fact of life. Settling into his new home, Martin is intrigued by a deserted house across the street and by an unfriendly neighbor, who seems t to be waiting for something to happen. Martin and new friends Granger and Holly form a club that meets in the deep end of an empty swimming pool. One night, Martin sees a light in the deserted house and the adventures of the Deep End Gang begin.