Watch Uncertainty

Bobby (played by Joseph Gordon-Levitt) and Kate (played by Lynn Collins), eleven weeks pregnant, are a youthful couple who has been dating for nearly a year. Unable to make up their minds on where to vacation for the Fourth of July or if they should have the baby, they decide to let fate make the choice. Bobby flips a coin, where they both run off the Brooklyn Bridge in opposing directions, with the storyline now split into a pair.

The first storyline occurs in Brooklyn, where Bobby and Kate have chosen to visit her family. During the trip, they decide to take a stray dog that they find, planning to find its owner. Kate's family and its secrets are revealed, including an institutionalized uncle with Alzheimer's, a brother who died half a decade ago, and a sister who is taking a year off before beginning college, despite the mom's protest.

The second storyline occurs in Manhattan's Chinatown, with Bobby and Kate finding a cellular phone which belongs to a killer, who values it at half a million dollars. When they try to meet for an exchange, avoiding the killer's pursuit, but Bobby tosses the phone onto a passing vessel.

Both of the storylines conclude the following day on a bridge with the same phrases uttered and the same questions asked.

The storylines are further delineated by Bobby and Kate's attire. In the second storyline, both are wearing easily recognized yellow outfits, while the Brooklyn storyline focuses on subtle greens. The first bridge scene has Kate in a yellow Manhattan dress, while Bobby wears the green Brooklyn outfit.

The underlying theme of the movie, as well as the likely inspiration for its title, comes from the Heisenberg uncertainty principle. This principle states that two particles will move in opposite directions from each other and have separate, yet similar qualities.