Victorian London and the hard rules of the circus form the backdrop to a friendship between young mudlark Clay and Mist, the last living wolf in the United Kingdom.

London, 1880.

Thirteen-year-old Clay is a mudlark, one of the countless boys who scavenge in the mud on the banks of the Thames looking for objects they can sell for a living. Together with his friends Tod and Nucky, known to everyone as the Terrors of Blackfriars Bridge, Clay spends his days by the river and wouldn’t exchange his freedom for anything in the world, certainly not for the three daily meals he would get at the Workhouses. One day, while trying to sell a valuable set of Tarot cards to a clairvoyant, Clay crosses the threshold of Smith & Sparrow’s Extraordinary Circus, which boasts of having “the last living wolf in the United Kingdom” in its menagerie. But wolves have been extinct for over three hundred years, everyone knows that. And so, when Clay runs into that very creature, with its silver coat and amber eyes, he can hardly believe it. Mist – that’s how the boy calls him – is a wild, fierce and indomitable beast. From that moment, Clay will try with all his might to set him free.