Top Marks for Murder — Robin Stevens

Daisy and Hazel return to their beloved Deepdean School for Girls only for a murder to put the school under threat of closure in this gripping eighth novel of the Murder Most Unladylike series.

Daisy and Hazel are finally back at Deepdean, and the school is preparing for a most exciting fiftieth anniversary celebration. Plans for a weekend of festivities are in full swing. But in the detectives' long absence, Deepdean has changed. Daisy has lost her popularity crown to a fascinating new girl, and many of the Detective Society's old allies are now their sworn enemies.

Then the girls witness a shocking incident in the woods close by -- a crime that they're sure is linked to the anniversary. As parents and alumni descend upon Deepdean, decades-old grudges, rivalries, and secrets begin to surface, and soon Deepdean's future is at stake. Can the girls solve the case and save their home?