WARNING: Spoilers ahead for Project Hail Mary. If you haven’t seen it, now is the perfect time to fire up your Prime subscription and watch. It’s worth it. I love a good needle drop, and Project Hail Mary has a perfect one with The Beatles' “Two of Us.” It’s actually rarer than you’d think to hear a Beatles song in movies, and as a huge fan of the lads from Liverpool, I’m always excited when it happens. It’s even better when the song's theme matches what the director (or directors, in this case) is going for in the movie, and Phil Lord and Christopher Miller nailed it with “Two Of Us.” Rocky Is Home For GraceThe song comes towards the end of the movie when Grace (Ryan Gosling) makes the decision to head back to find Rocky, rather than return to Earth. He sends the (appropriately named) beetles back to Earth to save humanity, then goes out to save Rocky. According to Miller, they chose the song because it’s about John Lennon and Paul McCartney and their friendship.Miller explained in the Blu-ray commentary why they picked “Two Of Us”:What's beautiful about the song is that it is about John and Paul and their long friendship that they've had over the years. And even though Ryland Grace is going away from his home, Earth, his real home is with Rocky. They also explained in an interview with Consequence that because the book pays tribute to The Fab Four, they felt they just had to include the song. Incidentally, it was actually producer Aditya Sood’s idea to use “Two Of Us,” because it was so perfect for the movie. (Image credit: Amazon MGM)The Sentiment Is Perfect, But The Song’s History Is A Little DifferentAll great art is, by design, open to interpretation, and The Beatles are no exception. “Two Of Us” is often thought of by Beatles fans as a song about John and Paul’s friendship, written as the band was on the verge of breaking up. And it is, but it’s also about McCartney’s relationship with his soon-to-be wife, Linda. Martney actually wrote the song on a recent trip he’d taken with Linda, and it's about her, really. According to McCartney (via BeatlesBible):One day we went out into the countryside and found a little wood that looked as if it might be a good place for a walk. I parked the car. There’s a photograph of me in the Aston Martin, sitting with the driver’s door open and my feet out. I’ve got my guitar. That’s me writing ‘Two Of Us’.The song is the opening track on The Beatles' final album, Let It Be, and because it’s a duet between Lennon and McCartney, Beatles fans have long interpreted it as being about the two of them. A coda, if you will, about their relationship and songwriting partnership. In fact, McCartney acknowledges that it is that, as well:Lying behind the phrase ‘We’re on our way home’ is less the literal sense of going back to London, but more about trying to get in touch with the people we once were. The postcard sending does have a very literal feel, though. Whenever Linda and I went away, we would buy lots of postcards and send them to all our friends. John was also a great postcard sender, so you’d get some great stuff from him.In the end, it doesn’t matter what inspired McCartney to write the song; Like all Beatles songs, they belong to the world, and that makes it the perfect needle drop in Project Hail Mary for all sorts of reasons.