A London detective pieces together a baffling series of crimes as an ominous grey face terrorizes the city in this hauntingly suspenseful mystery.

As a private investigator, Douglas Carey has solved his share of mysteries, but none so distressing or intimate as the one he is tasked with now. Having discovered a connection between a series of seemingly unrelated crimes—Carey's report promptly goes missing—along with several hours he cannot account for. In place of his lost memories, he sees only a sinister Grey Face.

Meanwhile, the Russian émigré Anton de Trepniak seems to have all of London society under his charming spell, along with the beguiling Madame Sabinov. As the Grey Face appears across London from Soho to Limehouse, Carey suspects the Russians are somehow involved. And uncovering the truth will reveal the most terrifying vision of all.