Agatha Raisin and the blood of an Englishman - M. C. Beaton

Even though Agatha Raisin loathes Christmas panto, her friend Mrs Bloxby, the vicar's wife, has persuaded her to support the local am dram society in their festive offering.
Stifling a yawn at the production of
Babes in the Wood, Agatha watches the baker playing an ogre strut and threaten on stage until a trapdoor opens... followed by a scream and silence!

Surely this wasn't the way the scene was rehearsed?
When it turns out the local baker had been murdered most horribly, Agatha puts her team of detectives on the case.
And they soon discover more feuds and temperamental behaviour in amateur dramatics than in a professional stage show - and face more and more danger as Agatha and her team get too close to the killer...