When twelve-year-old twins become owners of a time clock, they begin traveling back and forth through time, trying to solve the mystery of the strange Mr. Z who is a sinister presence in their lives.
Hardcover
(Delacorte Books for Young Readers, April 1, 1994)
Discovering how little the old repair man knows about the Branton Town Hall Clock, a Wonder of the World, the wise Clock Mice offer their assistance for its sake and theirs, only to find their confidences betrayed by the man.
Defines time and examines the many ways people have devised to measure its passage. Includes a variety of experiments that help explain the different aspects of time.