The video opens on Deschanel, 40, reading a newspaper as Perry walks her baby in a stroller.
Cut to space, where a pair of blue aliens are tracking the songstress in hopes of abducting her.
However, the aliens beam up the wrong celebrity when Perry and Deschenael briefly cross paths.
Inside the spaceship, the “New Girl” star is welcomed by a large group of aliens, who believe her to be Perry.
Deschanel attempts to explain the misunderstanding but it doesn’t seem to stick.
The aliens explain that it is, in fact, the end of the world, as they rescued the star about an hour before Earth is set to self-destruct.
Deschanel cons the two aliens responsible for the mistaken abduction into helping her save the planet.
The star is then suited up in one of Perry’s iconic looks — a bright blue wig. More references to the hit 2014 album “Teenage Dream,” including nods to the “California Gurls” music video, are featured.
Just in the nick of time, Deschanel is able to pull a plug disconnecting Earth’s internet.
“Earth is saved!” reads a monitor aboard the ship.
Deschanel and the aliens celebrate, as they chant, “Katy! Katy! Katy!”
The “Elf” actress then lipsyncs to the song while wearing a cosmic-themed outfit to perform for the aliens. They cheer loudly as Deschanel gives the camera a wink.
“Not the End of the World” was released earlier this year as part of Perry’s most recent album, “Smile.”
Perry welcomed her daughter, Daisy, this summer, shortly before the album’s Aug. 28 release.