Warning: (Writing as Anthony Morton)

A ruthless killer is on the loose and forces the John Mannering (aka 'The Baron'), a retired jewel thief and master cracksman, to once again step outside of the law in order to hunt down the murderer, and also save his own skin.

A victim had issued a cryptic warning before dying: 'Tell M. danger from Paul K'. It is clear Mannering is in extreme danger, but why, in what form the fatal blow might be delivered, and where he can start the pursuit remains to be deduced.

Events lead to a hair-raising trail in which Mannering cannot afford any mistakes.