The film is a post-apocalyptic fantasy that places the Clueless star right between the middle of family versus love.

A striking stranger named Jake, played by Drew Van Acker, has been living in a utopian world with his father Troy, portrayed by Stephen Moyer.

Once his father gets injured, Jake is forced to search for medicine in the outside world. Needing to put down anyone who steps in his way, Silverstone's Henrietta halts the lessons Jake has learned as they encounter one another with mysterious feelings getting involved.

"She's isolated herself and then she meets this boy man and he is so unusual. The lights in his eyes, it's what she wants the world to be like. There's so much hope in him," Silverstone said.

"This perfect reality that the father has created for them kind of slowly begins to unravel when his son encounters a mysterious stranger that slowly opens up his world view and kind of shifts his reality and perception he's known for his entire life," Acker said.

"Letting go is the hardest thing for him to do because he still feels that there are lessons he hasn't learned and that he might make mistakes," Moyer said.

Last Survivors in theaters and on demand now.