A jilted wife, a jealous mistress and a dead banker – the Parker sisters are up to their necks in trouble.

Martha Parker runs a small private detective agency in Glasgow with her two sisters, Helen and Geri. They specialise in catching cheating partners so when the Parkers are hired by the reclusive wife of a wealthy banker who suspects her husband is breaking their vows, they think they know what they’ll discover.

But when the husband shows up dead with his wife in the frame, it’s up to Martha, Helen and Geri to see if their client is an innocent woman – or whether they’ve got a vengeful widow on their hands…