Lord Peter Wimsey is on holiday in Kirkcudbright in South West Scotland, and on good terms with the artistic and local community there. When Campbell, a unpopular & quarrelsome landscape painter, is found dead in a burn near Newton Stewart (the Water of Borgan) it seems he must have accidentally slipped whilst painting near to the edge of a ravine.  But Wimsey is convinced the death wasn’t accidental and indeed an autopsy reveals that Campbell was dead before he fell into the burn.  There are six possible suspects, each with an alibi of sorts and all of whom had quarrelled with or been assaulted by Campbell, all of them artists.  The five innocent suspects are, of course, the five red herrings.

What follows is an intricately plotted story as Wimsey and the police investigate the mystery, culminating in Wimsey’s re-enactment of the crime from beginning to end to show how it was carried out.