First published in 1972 (as The Popinjay Stairs), this novel set in Restoration England is one of the finest productions in Geoffrey Trease's long and distinguished career as a writer of historical fiction for young readers.

The inciting incident for the novel's drama is the hold-up by highwaymen of a coach that numbers among its passengers one Samuel Pepys, Secretary to the Office of Lord High Admiral of England, and accordingly a young man who holds a high responsibility for the nation's naval defences. That the villains should relieve their victims of jewellery and watches comes as no surprise - but why are they so interested in the well-worn leather case of official documents belonging to Mr. Pepys?

What follows is a headlong tale of adventure, blackmail and treachery, culminating in a midnight river chase on the Thames.