Death on a cold, wild river: a Peter McGarr mystery

Chief Superintendent Peter McGarr, head of the Irish Police's elite Murder Squad, is a man under a cloud. Suspended for solving a very political murder that his superiors would rather have left unsolved, McGarr is struck by another misfortune when his old love, Nellie Millar, drowns in a flyfishing "accident." With altogether too much time on his hands, McGarr travels out to the ancient fishing village of Ardara, in the west of Ireland, to pay his last respects to the woman he almost married.
More than just his old flame, Nellie was also one of the recognized masters of the demanding art of flyfishing, and her angling school on the River Owenea drew wealthy students from around the world eager to learn Nellie's skill and absorb some of her famous fishing luck. It was that reputation, in fact, that drove her to attempt the dangerous outing on the night of her death, pursuing the imposing "trophy" salmon that had eluded her.
But something is definitely rotten in Ardara - Nellie was too good a river woman to be pulled down by a stumble, and a sinisterly clever slit in Nellie's watertight chest waders proves that her death in the river was no accident. And McGarr, once Nellie's student himself, can see that her killer must be an angler - no one else would know how fatal leaky waders could be in the Owenea at flood. Could it be Nellie's young lover, the flamboyantly grief-stricken American who styles himself as a "flyfishing cowboy"? The destitute salmon poacher who blames Nellie for reporting him to the authorities? Or the seductive Scottish divorcee who seems to have coveted Nellie's reputation and her lover? Suspension or no, McGarr knows that it's his job to find the killer. Bereft of his official authority, McGarr calls on his quirkily brilliant wife, Noreen, and his loyal Garda subordinates Hugh Ward and Ruth Bresnahan. Together, they pursue their quarry through smoky midnight pubs, Irish wakes, misty riverbanks, and the arcane complexities of world-class flyfishing.