The story is written in the style of a casebook and follows two fictional boarding schoolgirl detectives, Daisy Wells and Hazel Wong, as they try to find the murderer of their science teacher.

The book begins with Hazel recounting her discovery of the body of Miss Bell, the Science mistress, in the gymnasium on Monday 29 October 1934.

At bunbreak, Daisy discovers from talking to Henrietta Trilling (King Henry), who is the Head Girl, that Miss Bell resigned.

Daisy speaks to Jones about some windows broken in school and theorises that the damage could've been caused when the murderer moved Miss Bell's body.

At afternoon tea, Daisy spends it with fifth former, Alice Murgatroyd, which is unusual, as the students tend to remain with their own form.

By the end of Prayers the following morning, the news of the séance has spread across the school, and all of the students are aware of the possibility that Miss Bell was murdered.

The next day, they investigate Miss Tennyson's car and find a blood stain in it, leading them to believe they have solved the case.

When Miss Griffin realises that the detectives have discovered her crime, they hand the diary to the police and are sent to the San to be kept safe.

In its review, The Oxford Times praised Stevens for her "sense of place ... attention to detail, in-depth characters, authentic documents of events and, most importantly, absorbing plot".

[5] Children's author Jo Cotterill called it "extremely well plotted", but criticized the pacing of the story.

A casebook was also released with the tips and tricks on how to start your own detective society and much more, going by the name of Cream Buns and Crime.