A school production of "The Mikado". Katisha turns up dead. The Inquest says suicide. The Head suspects murder and asks Mrs. Bradley to investigate....
Needless to say, lots of suspects, motives, opportunities - the solution (a surprise, but interesting) reached by a circuitous, not always convincing, route. Gladys Mitchell seems more restrained in this third novel I have read, cutting back on eccentrics that have tended to populate. Mrs. Bradley, though, remains remarkably bizarre - she cackling, tiny and old, often compared with a crocodile (this last bit hard to picture).
Gilbert & Sullivan addicts may have a problem - it difficult to accept meek and mild Miss Ferris would ever have been cast in the first place as the awesomely overpowering Katisha. Another stumbling block is that serial killer just found not guilty of drowning his wife. Is it likely he promptly be inviting people into his home so he can dispose of them in his bath?
It is wise not to question certain aspects too deeply. Treat the novel as fun, a leisurely read. I enjoyed it.