July 1910: The grisly remains of Cora Crippen, music hall singer and wife of Dr Hawley Crippen, are discovered in the cellar of 39 Hilldrop Crescent, Camden. But the Doctor and his mistress, Ethel Le Neve, have vanished, much to the frustration of Scotland Yard and the outrage of a horrified London.

Across the Channel in Antwerp, the SS Montrose sets sail on its two week voyage to Canada. Amongst its passengers are the overbearing Antonia Drake and her daughter Victoria, who is hell-bent on romance, the enigmatic Mathieu Zela and the modest Martha Hayes. Also on board are the unassuming Mr John Robinson and his seventeen-year-old son Edmund. But all is not as it seems...