Topher's amazing cat, Ka, has time-traveled again, leaving him another
mysterious clue. Topher finds himself in Victorian London, where disease
is rife and the Thames is clogged with stinking sewage! There he
discovers a plot to kill Joseph Bazalgette, the man trying to save the
city. Determined to foil this foul plan, Topher must first escape from
an arch-criminal and his den of thieves.