Daffodil, a quiet cabhorse, is stolen from his stable in Yorkshire, in preference to a much more valuable animal in the next stall. Curious, but hardly a matter for Scotland Yard, especially in wartime. But when an influential widow pulls some strings, Inspector John Appleby is assigned to the case. He discovers that Daffodil has a remarkable affinity for numbers, even seeming to know when people are thinking about them.
Meanwhile Appleby's colleague Hudspith, a specialist in the abduction of young women, is investigating the disappearance of Lucy Rideout, a London waitress. He realizes she is suffering from undiagnosed dissociation, having three distinct personalities. Appleby discovers the two cases are linked with the bizarre theft of a haunted house, which was dismantled and removed piecemeal from a London square under the cover of the nightly bombings.
The trail leads to South America. Appleby and Hudspith take passage on a cargo ship, posing as Australian wool merchants. Among their fellow passengers are some psychic individuals, apparently being collected by Mr Wine who is obsessed with unusual phenomena of all kinds. Appleby induces Hudspith to pretend to see visions, to pique Wine's interest, but the imposture is later exposed. Wine then affects to believe that the two policemen are actually representatives of a rival psychic investigator, and invites them to his scientific research station.
The station is on an archipelago in the Amazon, more than two thousand miles downstream. On the river voyage, Appleby befriends Lucy in each personality - Young Lucy, Sick Lucy and Real Lucy. He hopes that she will be a valuable ally in dealing with Wine, whose aims seem increasingly sinister.
This report prepared by Maureen Evans