In 1930s England, schoolgirl detectives Daisy Wells and Hazel Wong are at Daisy's home for the holidays when someone falls seriously, mysteriously ill at a family party, but no one present is what they seem--and everyone has a secret or two--so the Detective Society must do everything they can to reveal the truth . . . no matter the consequences.

The fantastic new mystery from the author of Murder Most Unladylike. Daisy Wells and Hazel Wong have returned to Deepdean for a new school term, but nothing is the same. There's a new Head Girl, Elizabeth Hurst, and a team of Prefects - and these bullying Big Girls are certainly not good eggs. Then, after the fireworks display on Bonfire Night, Elizabeth is found - murdered. Many girls at Deepdean had reason to hate Elizabeth, but who might have committed...

When Daisy Wells and Hazel Wong set up their very own secret detective agency at Deepdean School for Girls, they struggle to find any truly exciting mysteries. Little do they know that in the months that follow, mystery - and murder - will never be far away, and when Hazel discovers the Science Mistress, Miss Bell, lying dead in the Gym, the Detective Society is determined to get to the bottom of the crime. Then, soon afterwards, there's the incident...