Schoolgirl detectives Daisy Wells and Hazel Wong are at Daisy’s home, Fallingford, for the holidays. Daisy’s glamorous mother is throwing a tea party for Daisy’s birthday, and Daisy’s eccentric family are all invited.

Then one of their party falls seriously, mysteriously ill – and everything points to poison.

With furious storms preventing anyone from leaving, or the police from arriving, Fallingford suddenly feels like a very dangerous place to be. No one at Fallingford is what they seem – and everyone has a secret or two. And when someone very close to Daisy looks suspicious, the Detective Society must do everything they can to reveal the truth… no matter the consequences.