Themes & patterns

The book opens with a philosophical meditation on the ethics of wills and property disposal, and the entire plot revolves around a contested inheritance that drives the cousins' conflict and the mystery.

Characters adopt false names, fake alibis, and elaborate disguises (such as Nigel posing as Mr. Quirk), while the central mystery hinges on whether Derek is alive or dead and who is really who.

The contrast between Derek's conventional, dissipated lifestyle and Nigel's affected aesthetic poses highlights tensions within the English upper classes, with Nigel's disdain for 'unforeign' things and his theatrical 'river-man' costume.

The idyllic Thames setting is described in lush, natural detail, while characters like Nigel prefer artificiality—he dislikes flowers outdoors, praises photography for never telling the truth, and dresses up for effect.

The two cousins, Derek and Nigel, are locked in a bitter personal feud marked by mutual avoidance, public insults, and ultimately a plot to frame one another for murder.

The narrative follows detective Miles Bredon as he systematically analyzes clues—footprints, photographs, ciphers, and timings—to reconstruct the truth behind the apparent drowning.

Nearly every piece of evidence (the canoe, the footprints, the photographs, the two purses) is shown to be a deliberate construction or misinterpretation, underscoring how easily appearances can deceive.

Derek's elaborate scheme to frame Nigel for murder stems from his belief that Nigel caused a woman's death and escaped punishment, turning the plot into a twisted form of moral vengeance.