The film stars Kaitlyn Dever as a young seamstress living alone, shunned by the local townspeople, who must fight off a home invasion by gray aliens and their associated parasites that has unexpected consequences.

Mourning the loss of both her best friend, Maude, and her mother, Sarah, Brynn copes by constructing a model town in her living room.

Brynn flees the town on a bus, but several passengers attempt to restrain her and are revealed to be controlled by alien parasites placed in their throats.

She apologizes to Maude before breaking free of the hallucination and pulling the parasite from her mouth, finding herself lying in a field.

[2] In April 2021, it was reported that 20th Century Studios had acquired the script, with Duffield set to direct and Kaitlyn Dever attached to star.

[3] On an estimated budget (before tax incentives) of $22.8 million, principal photography took place in New Orleans from April to June 2022.

[12] JustWatch, a guide to streaming content with access to data from more than 20 million users around the world, reported that No One Will Save You was the third most-streamed film in the U.S. during the week of September 18-24, 2023.

The website's consensus reads: "A home invasion thriller with an extraterrestrial twist, No One Will Save You serves up more genre fun from writer-director Brian Duffield – and proves Kaitlyn Dever doesn't need much dialogue to command the screen.