After an excellent 1989 adventure and a bogus 1991 journey, happy-go-lucky time-traveling dudes Bill (Alex Winter) and Ted (
Keanu Reeves) are now middle-aged BFFs who need to fulfill their destiny and write a song that will save the universe. Thankfully, when time and space come unglued, help arrives courtesy of their loving teen children, Ted's daughter Billie (Brigitte Lundy-Paine) and Bill's kid Thea (
Samara Weaving). "They do everything together, finish each other's sentences," director Dean Parisot says of the girls. "And they're musically brilliant, almost savants when it comes to knowing every single thing about music throughout history. So they're sort of fantastic, crazy geniuses."