Sophie, a British Youtuber, brings her two friends Jessica and Lisa along for a trip through Southern California. The trio arrives in Los Angeles, documenting nearly every minutes of their journey but after a rowdy night of partying with new friends, Sophie begins to second guess bringing the two with her. While confiding this to her viewers, she finds a note on the windshield of their car with a cryptic message. Tensions rise between the three girls as more messages from an unknown source flood in from social media and one of their missing phones.