A clear crime hides an untold secret . . . London, 1882. American agents Henry and Johanna McClellan need the help of the World's End Bureau to find Bruno Schmidt, a cunning lecturer who cajoled a young American woman called Ava into eloping to Europe. Now Ava's father wants her back. Though the McClellans have followed the missing pair's trail to London, they can't find their way around the busy city without help. PI duo Lily and Felix accept the case and soon discover a promising clue regarding Bruno and Ava's whereabouts. But the more Lily and Felix investigate, the more complicated and implausible this seemingly straightforward case becomes. Their suspicion quickly falls on their clients, who might not be as honest as they first seemed to be . .