Lorac, the pen name of the British writer Edith Caroline Rivett.

[1][2] It was the twelfth entry in her long-running series featuring Chief Inspector MacDonald of Scotland Yard.

[3] It was written shortly after Lorac had been elected as a member of the Detection Club, and was likely influenced by her experiences there.

MacDonald is invited to the London home of a publisher to take part in a treasure hunt based on various intellectual clues against various authors, everyone using the alias of a celebrated historical writer.

When an obnoxious but bestselling crime novelist is found dead things take on a more serious turn.