Kennedy Blaine, a Californian girl, inherits a ranch in the small town of Valentine in Nebraska. Before she sells the property, she decides to spend the summer in her house and learn more about her family.

A young married couple makes a huge mistake by agreeing to participate in a secret swingers' party in their suburban neighborhood, and soon both of them are being targeted by a jealous and homicidal neighbor.

A wanderer named Jack DiMercurio secretly desires the life and wife of his more affluent friend, Andy Shelton. Past tensions resurface between the two men during an informal reunion at Andy's cottage on Lake Michigan. One heinous act allows Jack to draw close to Andy's wife Liz, but Jack finds living Andy's life is a dangerous lie.

Sum of Us intertwines 10 connected stories across generations that deconstruct the myths surrounding the creative journey and what it truly means to be a storyteller.