It is 1862, though not the 1862 it should be. Time has been altered, and Sir Richard Francis Burton, the king's agent, is one of the few people who know that the world is now careening along a very different course from that which Destiny intended. When a clockwork-powered man of brass is found abandoned in Trafalgar Square, Burton and his assistant, the wayward poet Algernon Swinburne, find themselves on the trail of the stolen Garnier Collection of black diamonds rumoured to be fragments of the Lemurian Eye of Naga, a meteorite that fell to Earth in prehistoric times.

His investigation leads to involvement with the media sensation of the age: the Tichborne Claimant, a man who insists that he's the long lost heir to the cursed Tichborne estate. Monstrous, bloated, and monosyllabic, he's not the aristocratic Sir Roger Tichborne known to everyone, yet the working classes come out in force to support him. They are soon rioting through the streets of London, as mysterious steam wraiths incite all-out class warfare. From a haunted mansion to the Bedlam madhouse, from South America to Australia, from séances to a secret labyrinth, Burton struggles with shadowy opponents and his own inner demons, meeting along the way the philosopher Herbert Spencer, Isambard Kingdom Brunel, Florence Nightingale, and Charles Doyle (father of Sir Arthur Conan Doyle).

Can the king's agent expose a plot that threatens to rip the British Empire apart, leading to an international conflict the like of which the world has never seen? And what part does the clockwork man have to play? Burton and Swinburne's second adventure, The Clockwork Man of Trafalgar Square is filled with eccentric steam-driven technology, grotesque characters, and a deepening mystery that pushes forward the three-volume story arc begun in The Strange Affair of Spring Heeled Jack.