The third in the FFSG series.

Detective Sergeant Frank Summers is in the doghouse with the three most important women in his life (apart from his mother, obviously): his boss, Detective Inspector Frieda Garold, the most attractive boss he's ever known; his maybe, maybe-not girlfriend "Dr Death" also known as the local pathologist Susan Pleadle who has the shortest fuse he has ever known, and Giggling Gertie, his assigned constable, who has the fastest mood-swings he has ever known.

Since he's in their bad books (because he had invited Frieda's new, young secretary to his flat on his birthday) he has resorted to working weekend and night shifts to keep out of their way. The consequent tiredness slowed his thought processes during the day, and in a moment of forgetfulness while in a supermarket, he arrested an internationally-sought con-artist whose photograph he recognised from the Interpol poster which he had used as something on which to write his shopping list.

According to the poster police forces from around the world were anxious to have a word with the diminutive Frenchman who called himself M Guillaume Matisse. Frieda was delighted that her own station and her own team had succeeded where so many had failed. Frank is more than willing to let her take all the credit, as he has no wish to get involved with something he increasingly feels isn't what it appears to be.

Word comes that the French Sûreté are sending over one of their finest officers, one Capitaine Jean Tromperie. Frieda assures Frank that she will look after the gallant, and no doubt handsome, French officer. Frank's urge to keep well clear increases: as he points out, 'tromperie' is French for 'deception'.

The delightful Capitaine turns out to be very good-looking - and a young woman. And has a sneer for everything English. Within a few hours she has the entire station dearly wishing to replay Agincourt in a personal sense. But again Frank suspects that she isn't all she's claiming to be.

Then the officers from Scotland Yard turn up, two bruisers calling themselves Detective Superintendent Campbell and Detective Sergeant Hovis. This time Frank is quite certain they're frauds. But he doesn't tell Frieda, because they're not talking to each other. Until it's too late, and Wellbury is locked down with the entire force searching for two armed convicts who have kidnapped Gertie. By then the French Capitaine has disappeared with M Matisse, but that's the last of their problems.