A small-time confidence trickster on the run stumbles across a sinister organisation, based at a manor house in the Cotswolds, who are using a high-class clinic as a front for their more dishonest activities. About to be killed by them, he manages to turn the tables, steal their formula and make an escape. Pursued by his ruthless adversaries, he manages to reach Oxford and stash the stolen formula in the Bodleian Library before he is recaptured. Coincidentally Appleby is also in the city, called in by his younger sister Jane to find her fiancée, an undergraduate who is gone missing. It turns out that he has vanished in the vicinity of the manor house, as has a refugee Austrian doctor and her young son.

Only when Jane penetrates the clinic does she discover the full extent of the scheme. What the confidence trickster had thought was an alchemist's operation to produce gold or at the very least forged five pound notes is in fact the development of a brainwashing technique that destroys any sense of human independence or resistance. The scheme is codenamed Operation Pax.

• Hubin, Allen J. Crime Fiction, 1749-1980: A Comprehensive Bibliography. Garland Publishing, 1984.
• Reilly, John M. Twentieth Century Crime & Mystery Writers. Springer, 2015.
• Scheper, George L. Michael Innes. Ungar, 1986.