Rebecca's on-again, off-again boyfriend Ezra has gone missing, but the police seem surprisingly unconcerned. They suspect he has been playing the "stranger game," a viral hit in which players start following others in real life as they did on social media. As the game spreads, however, the rules begin to change, play grows more intense and disappearances are reported across the country. Hoping to track down Ezra, Rebecca tries the game for herself. She meets Carey, who is willing to take the game beyond what she imagined possible. What could lead Rebecca to Ezra may also take her further and further from the life she once lived.