High school senior and aspiring inventor David Raskin (Jonny Weston) is admitted into the Massachusetts Institute of Technology, but is unable to afford its tuition fees. Upon learning his mother, Kathy (Amy Landecker), is planning to sell the house, David enlists his sister Christina (Virginia Gardner) and his friends Adam Lee (Allen Evangelista) and Quinn Goldberg (Sam Lerner) to search through the belongings of his father Ben (Gary Weeks), an inventor who died on David's seventh birthday, in the hopes of finding something David can use to get a scholarship, filming themselves all the while. He finds an old camera with a video recording of his seventh birthday party, in which he briefly spots himself in a reflection. Noting how he appears to be reaching for a basement light switch in the reflection, David and his friends go to the basement, which his father forbade. The group pull the switch, activate a trapdoor, find blueprints for a time travel device that Ben was developing called "Project Almanac", and build a functional time machine. They successfully send a toy car back in time, but blackout the entire neighborhood. While they get caught by David's crush Jessie Pierce (Sofia Black-D'Elia), whose car battery they used to power the device, they recruit her into their experiment.