An atmospheric, intricately plotted new mystery in which Sherlock Holmes and Henry Vernier race to catch a villainous murderer at large in the Vatican and Rome.

While Sherlock Holmes and his cousin, Henry Vernier, are in Rome on a diplomatic mission involving the Vatican, the Pope asks the world's greatest detective to help find a stolen relic: the missing forefinger of "doubting" Saint Thomas.

When the relic is quickly and mysteriously returned, all seems to be resolved. But events are turned upside down when the relic disappears again.

With fresh blood spilled, Holmes and Vernier must follow the trail of a sacrilegious murderer through the streest of Rome, the halls of the Vatican, and beyond.