Cameron Diaz and Harvey Keitel star as the happy couple. What we know about Nathalie is that she's trying to avoid pills and alcohol, little habits that first brought her into her husband's orbit when she appeared before him in court. Drops in, and then drops dead. Her guilt, compounded by what some would call her abject stupidity, ends up pulling everybody into a big mess.
Suspicion falls on everyone.
What stops Head Above Water from being a big load of fun is mostly the pacing. Because the picture is so plot-driven, and clumsily, the characters are never developed to the point where you'd believe what's going on. Diaz mostly bites her lip, parades around in a bathing suit and turns those blue headlamp eyes of hers on the camera. Keitel needs only one whiskey to go from sedate judge to Texas Chainsaw Massacre wannabe. And there are a few clever O Henry-ish twists and turns to the story.