Summer 1930. In a leafy suburb of Torquay of the English Riviera, twin sisters Kitty and Nora Markham enjoy a privileged life. Interested in amateur sleuthing and looking for adventure, they enjoy some success in finding runaway cats and lost purses.

However, when a shocking murder is committed a stone’s throw from their home, they decide to do some serious investigating, teaming up with their neighbour Arthur Westacott, son of the Chief Constable, and James Keyse, great-nephew of their housekeeper and newly appointed police constable.

It seems like an open and shut case, as a man is immediately arrested and charged with this most deplorable of crimes. However, when Kitty, Nora, Arthur and Jimmy start digging a little deeper, they soon discover a deliciously twisting case that isn’t as clear cut as everything first appears.