Winner of the Betty Trask Award 2016, nominated for the Authors' Club Best First Novel Award 2016, and finalist for the Locus First Novel Award 2016. An international bestseller, a Guardian Summer Book, an Amazon Best Book of the Month, a Goodreads Best Book of the Month, a Buzzfeed Summer Book, a Foyles Book of the Month, a Huffington Post Summer Book, and a Yorkshire Post Book of the Week.

In 1883, Thaniel Steepleton returns to his small apartment and finds a golden pocket watch on his pillow. When the watch saves Thaniel's life during an explosion that destroys Scotland Yard, he sets out to find its maker, Keita Mori - a kind, lonely Japanese immigrant. Meanwhile, Grace Carrow sneaks into a library in Oxford, desperately trying to prove the existence of the luminiferous ether before her mother can force her into marriage. As the lives of these three characters become intertwined, events spiral out of control until Thaniel.