If you read the book Project Hail Mary, you wouldn’t know the twist until page 170.

But you only have to watch the trailer for the movie based on the 2021 novel of the same name to find out (spoiler alert!) among other key plot points, that one of the main characters is an alien that he names Rocky. But the book’s author, Andy Weir, is more than ok with that.

Project Hail Mary the movie stars Ryan Gosling as Ryland Grace, a teacher who wakes up in space with amnesia. As he slowly figures out why he, a science teacher and not an astronaut, is on a spaceship rather than in a classroom, he meets the higher life form that’s going to help him on his mission (once he finally recalls it) to save our planet from certain destruction.

But like we said, Weir, who also wrote The Martian, also adapted into a film, was on board with the reveal. “The idea was no one’s going to walk into that theater and not know about Rocky,” Weir said in a recent interview. “This is not a ‘Darth Vader is Luke’s father’ kind of situation. This is a core, central element of the plot that everybody’s going to be talking about and that everybody who’s read the book already knows about.”

Project Hail Mary was directed by Into the Spider-Verse‘s Chris Miller and Phil Lord, with Drew Goddard adapting the screenplay. Sandra Hüller, Milana Vayntrub, Lionel Boyce, and Ken Leung also star.

Amazon MGM and Sony Pictures will release Project Hail Mary to theaters on March 20th, 2026.