Along the Allegheny River in the small town of Starbrick, Pennsylvania, Mike and Eydie Rossi return from fishing, mooring their boat at the end of a stretch of houses lining the riverbank. The Rossi’s house is situated fifty yards across an easement that skirts the bottom of the property belonging to neighbor, Chad Walker. As the Rossi’s walk to their house, Walker, a grumpy, retired attorney, accosts Mike and threatens to shoot him for trespassing on his land. Sick and tired of Walker harassing him, Mike explodes, insisting that he won’t drive five miles around the houses to the boat marina when his house is just fifty yards across the path. He tells Walker that the piece of land is public access. And like the others on the stretch of river he’ll park his boat as close to his house as possible. Chad, furious, argues back, while Eydie tries to stop Mike from making a fool of himself by having a shouting match with an old man.
The battles continue, until one day Mike comes home to find Walker waiting under a tree, aiming a gun at him. Terrified, Mike calls the police. They point out to Mike how many times Walker has complained about him, then take a conflicting statement from Walker, who tells them he acted in self-defense. Suspicious of the way the incident is handled, Mike sets out to form a river committee against Walker and his belligerence. Eydie, furious with Mike for continually goading Walker, accuses her husband of starting a war against their neighbor, insisting that he’s the problem, not Walker.
Relentless, Mike checks out new property markers along the path only to be confronted by Walker and a shotgun. A heated argument develops. Walker pulls the trigger and kills Mike.
Devastated, Eydie attends the preliminary hearing only to have the case dismissed on grounds that Mike died accidentally. Horrified that Walker now roams around a free man, she sets out on a quest to find out the truth behind her husband’s death and becomes the laughingstock of the town, enduring humiliation from neighbors, friends, and family.
Eydie then puts her own life in danger when upon discovering Mike’s diary, she pieces together a jigsaw puzzle that proves a land scam in the town with a prominent local figure as the ringleader and Walker as his accomplice.
Walker quickly finds out Eydie is not a push over and urges her arrest for interfering in the plan. When Eydie, with evidence in hand, heads out to prove Mike’s death was murder, a violent storm causes the river to burst its banks, leaving the road impassable. The only way out is by boat. But there’s only one, hers, and it’s across the divided path.