The Deep End gives off a sweet malevolence; it softly seduces you even as it fills you with dread. Unlike some popular thrillers, The Deep End doesn't nudge you with mechanical scare tactics to provide tension. The picture is both intelligently suspenseful and an incongruously witty chamber drama. Scott McGehee and David Siegel, the co-writers and co-directors, quietly and shrewdly build our apprehension by having us slowly come to empathize with a main character who paves her road to hell with the best of intentions.
Tilda Swinton (I Am Love, The Grand Budapest Hotel) plays Margaret Hall, a lonely housewife in Lake Tahoe, who spends her days dutifully carrying out all those mundane domestic chores of motherhood. Her husband, meanwhile, is a naval officer who spends his days carrying out his duties at sea. In short time, though, Margaret finds herself at sea emotionally when she discovers that her eldest son, Beau (Jonathan Tucker), is gay. She also comes to see that his lover, Darby (Josh Lucas), is a rather disreputable character who might bring harm to her son. Margaret initially pleads with Darby to stay away from Beau, but he ignores her, and later makes a midnight creep from Reno to Lake Tahoe. When Beau gets into a skirmish with his lover on the family dock, Darby is accidently killed. In the morning, Margaret finds the body and assumes that her son has committed murder. While Beau has no knowledge of of what happened, Margaret does what any loving mother might do; she tries to clean up the mess and protect her family. Based on the little-known 1940s novel, The Blank Wall, by Elisabeth Sanxay Holding (which was also the source for Max Ophuls 1949 film noir, The Reckless Moment), The Deep End is largely anchored by Swinton's complexly layered performance.