When Harry discovers that the most evil villain in the galaxy, Galactic Gary, has escaped from prison, it's not just humankind that is in danger, but time itself.

Galactic Gary is trying to discover the whereabouts of a special time bomb that muddles the days of the week. Wednesday can become Saturday and Sunday can become Tuesday! The parts of the bomb are hidden on three different planets and the boys are in a rapid race to recover them. It's up to Harry and Colin to save the day (again!) in this action-packed, light-speed adventure.

This title is the fourth instalment in the 'Cosmic Colin' series.