Sergeant Verity's second adventure sees him sweltering under the Indian sun, as mutiny brings pillage and war to Bengal. Attached to the Intelligence Department in Calcutta, Verity is given the task of tracing English women who have fallen into the hands of the mutineers, and who face death - or an even worse fate in the harem.

But this task is supplanted by a yet more desperate quest when the Kaiser-i-Hind, the great diamond which symbolises sovereignty over all India, disappears, as if by magic, from beneath Verity's eyes as it is about to be handed over to the British.