To be frank, I bought this book because on Amazon it looked like it was part of the British Library Crime Classics series, so I thought it was. It turned out to be bare-bones, print-on-demand—but actually quite a surprise.
The amateur sleuth is Sir John Saumarez, a famous actor-manager. But he doesn’t get actively involved until after the trial.
A second- or perhaps third-rate acting company is putting on a play in a town in Wales when Magda Druce, an actress and wife of the manager, is found dead, her head bashed in by a poker. With her and holding the poker is another actress, Martella Baring, who invited Magda for a late supper. She must have murdered Magda, but she seems confused and keeps asking what happened.
At her trial, both the prosecutor and the defense assume Martella did it, but the defense posits that she was in a fugue state. John Saumarez, who vaguely recognizes her name from an interview in which he encouraged her to get more experience, has attended the entire trial. He wonders what emptied the brandy flask, since Martell testifies that neither she nor Magda had any brandy. She is found guilty, but to Sir John, it doesn’t add up.
Sir John summons Novello Markham, the production’s stage manager, to his office, because Markham was one of the first on the scene. Soon, he, Markham, and Markham’s wife, Doucebell Dearing, are on their way back to Wales to investigate. Sir John thinks someone else may have come into the room from the back window. It seems clear that person must be one of two young men in the company—Ion Marion or Handele Fane.
I found this novel surprisingly good. It’s not extremely complicated, as many mysteries written in 1928 seem to be, yet it’s not easy to know who the killer is. The characters are interesting, and the authors seem to know quite a bit about the theatre.
It turns out that Clemence Dane was a successful novelist and screenwriter, an Oscar winner, whereas Helen Simpson won the James Tait Black Prize for fiction in 1932. The two wrote three mysteries, and this is the first. It was made into the movie Murder! by Alfred Hitchcock.
What? Me Read? 
That’s a happy mistake!
Yes, it is!