Based on a true story, "Lost Transmission" follows Theo Ross (Simon Pegg), a respected Los Angeles music producer and his friend, Hannah (Juno Temple), a shy, aspiring songwriter, who discovers that he has lapsed on his medication for schizophrenia. In an effort to get Theo the help he needs, Hannah and their group of friends, chase him as he outruns his colorful delusions through the glamour and grit of Los Angeles' music scene.