The plots revolve around the “locked room” mystery from amateur sleuthhounds Antony Gillingham and Bill Beverley. Both had become acquainted a few years earlier and happened to meet at the Red House. Red House was owned by Mark Ablett, a philanthropist. The house party was shocked by a gunshot, and it turned out that Robert Ablett was killed in a locked room. Robert was Mark's long-lost brother who just arrived from Australia. The deceased and his brother had never been on good terms. As a result, a court of law has decided Mark guilty by some 'last seen theory'. But it was not an ordinary crime because Mark was never found at the scene. Hah! That's the case.
The author does not provide enough clues for the reader to work out in this soft-boiled mystery, but in the end, it's really all about the final twist and a devilishly family skeleton.
Thanks to @NetGalley and Pushkin Vertigo for providing a free copy in exchange for an honest review!