The British Empire reigns supreme, and its young Queen Victoria has expanded her realm to St. Francisco, a bustling city of English lords and Chinese ghettos. St. Francisco is a jewel in the Empire's crown and as deeply embroiled in the conflict between the Arcane and Science as its sister city, London—a very dark and dangerous battle.

Marcus Stenhill, Viscount of Westwood, stumbles upon that darkness when he encounters a pack of young bloods beating a man senseless. Westwood's duty and honor demand he save the man, but he's taken aback to discover the man is Robin Harris, a handsome young inventor indirectly responsible for the death of Marcus's father.

Living in the shadows following a failed coup, Robin devotes his life to easing others' pain, even though his creations are considered mechanical abominations of magicks and science. Branded a deviant and a murderer, Robin expects the viscount to run as far as he can—and is amazed when Marcus reaches for him instead.