The notorious inhabitants of London's criminal underworld are all in a day's work for Mog, the young printer's apprentice, who prints their WANTED posters. But then a real-life meeting with a genuine convict entangles Mog in a secret scheme that has all the crooks of the city at each others' throats. An ingenious theft, a series of mistaken identities, and a chilling murder all connect to a ship just docked from India, and Mog's own mysterious past... Evoking Philip Pullman, Caleb Carr, and Charles Dickens, first-time writer Paul Bajoria's original voice and vivid, suspenseful storytelling will enchant young readers.

Sent to live with their nearest living relative, Sir Septimus Cloy, the eccentric widower of their late mother's cousin, Mog and Nick spend a lot of time on their own. They explore the Cloy mansion, with its towers and turrets, staircases leading nowhere, and forbidden rooms. Two elderly manservants, Melibee and Bonefinger, guard Cloy like malevolent ravens. Then sinister things begin to a falling gargoyle misses them in the churchyard, a flagstone collapses beneath their feet, and their governess is found hanged in her room. References in old documents point to some dark secrets in the history of the house, and the village is rife with rumors. Is the mysterious Damyata, a villian from Mog's past, at large once again? And can the twins discover the truth behind the family mansion and its secrets, before their own lives become endangered?

Mog and Nick travel to Calcutta, in India, the country of their birth and the supposed location of the mysterious Winter diamond. Their family has owned the diamond for generations, and when they learn that a ruthless sea-captain is intending to seek it out and make his fortune, they determine to beat him to it and claim what is rightfully theirs. But when they arrive in Calcutta, they soon learn that the diamond also has far more sinister powers, and as they pursue their quest, the shadowy figure of Damyata is never far away