Lew Harper (Paul Newman) travels to Louisiana at the behest of Iris Devereaux (Joanne Woodward), an heiress and ex-mistress being blackmailed by parties unknown. Harper grows ensnared in a feud between Iris's mother (Coral Browne) and oil tycoon Kilbourne (Murray Hamilton) over land rights, with the crooked police commissioner (Tony Franciosa) and assorted other lowlifes also playing a part. As bodies start piling up around the bayou, Harper finds his own life in danger.
Largely jettisoning Macdonald's novel, The Drowning Pool offers a conventional set-up with duplicitous femmes, double-crosses and dirty cops. The script (credited to formidable scenarists Walter Hill, Lorenzo Semple and Tracy Keenan Wynn) affords few surprises: the villain's pegged from the word go, and other roles, while colorful enough, register as types rather than full-fledged characters. Harper merely bounces off them according to plot diktats, rather than truly interacting. His relationship with Iris, in particular, is too flat for the emotional beats to land; Harper has more chemistry with Kilbourne's wife (Gail Strickland), in far fewer scenes together.
Luckily, The Drowning Pool does have its merits. Stuart Rosenberg's direction is slick if not outstanding, with photographer Gordon Willis making great use of Deep South imagery: bird-crowded greenhouses, towering mangroves, steaming swamps and garish, neon-lit bungalows. Several scenes take place in a warehouse where old Mardi Gras floats; a nocturnal showdown has masked goons confronting Harper with shotguns and road flares in a murky swamp. The central set piece has Harper and Ms. Kilbourne trapped in a flooding hydrotherapy room, staged with well-timed, nail-biting suspense.
Paul Newman coasts through the film, leaning on his laconic presence and taciturn wit. Supporting players provide more colorful turns: Murray Hamilton's oily oilman, Tony Franciosa's brutal police chief, Andy Robinson as his trademark sleazebag, Richard Jaeckel as a crooked cop eaten by dogs. Joanne Woodward and Coral Browne are underused, but Gail Strickland scores as Hamilton's put-upon wife. Melanie Griffith plays a squeakily seductive teenager, similar to her role in the same year's Night Moves.
The Drowning Pool is entertaining enough for undemanding genre fans: even Paul Newman on autopilot makes a charming lead, and there's enough twists and inventive violence to redeem the sluggish passages. It's just mildly disappointing that with so much talent on board, the filmmakers couldn't produce more than a passable time waster.