Close to London, the tiny and fanciful town of Amersham is shaken by a sudden spate of homicides, starting with the murder of Jane Ferrier as she's walking home from work.
Each month that comes along leads to the death of another young woman: Sarah Parker is killed while on holiday with her boyfriend, whereas young lawyer Michelle Pearson meets her grisly end in a crowded public park.
With each murder taking place exactly one month apart on the 15th day, it's a race against time to find the killer before the next woman is taken.
Add in the fact that each death has involved a poisonous dart and a green-eyed, blonde-haired victim, and the mystery deepens.
Why were these women targeted? Does it have anything to do with their history of turbulent love affairs? And who could possibly have the knowledge and means to kill with poison-tipped darts?
With Chief Inspector Patrick Campbell in charge of the cryptic case, he must get to the bottom of the murders before anyone else gets hurt.
As the murderous riddle unfolds, we meet a whole host of intriguing characters who could help the Chief Inspector hunt down the murderer, but with his leads running out fast, will he finally end the trail of blood… or add to it with his own?