Mark Helston, the rising star of Hunt Coffee Limited, was successful and popular, with plenty of money and everything to live for. Yet at half past seven on the evening of the ninth of January, 1925, he walked out of his Albemarie Street flat and disappeared. Desperate to know what happened to Mark, his uncle, old Mr Hunt, appeals to Jack Haldean. Inspector Bill Rackham of Scotland Yard thinks it's a thankless task. Perhaps, says Jack, but why should Mark Helston vanish? And then Jack finds a body...