Smoke and Mirrors by Elly Griffiths
Smoke and Mirrors, the second book in Elly Griffiths series featuring DI Stephens, and actor/magician Max Mephisto, is set in Brighton about a year after the events in the Zig Zag Girl, during the winter of 1951. Max and the Great Diablo are performing in a pantomime in town. These type of pantomimes seem to be a very British thing. It's a theater play that involves music, topical jokes, and slapstick comedy, and in this case magic, and is based on a fairy tale or nursery story. They are usually produced around Christmas, I'm not sure why.
When two young children go missing, and are later found dead in a snowbank surrounded by candies, DI Edgar Stephens, and his officers, Emma Holmes and Bob Willis, are tasked to investigate. With a frightened community demanding that the killer be found, and little evidence to go on, Stephens turns to his old friend Max for information after drawing a possible link to...