The Twilight Saga: Breaking Dawn – Part 1 is set to hit theatres this November, and it’s been revealed that a new Bruno Mars song called ‘It Will Rain’ will be the lead single off the soundtrack.

The track is set to be released globally tomorrow, and in an interview with Billboard, Mars says the track was written on the road and says, ‘after seeing the movie, I thought that it would be a perfect fit.’

Mars told Billboard that “the ‘Twilight’ movies for me (are) a love story. But it’s a dark love story. And I think the best way to describe the song is: it’s the darker side of love. I think that pretty much sums it up.”

“It Will Rain” “started off with me and the guitar,” Mars says, “and I just had this melody in my head and basically laid it down after I saw the film.’

Look for a full tracklisting of The Twilight Sage: Breaking Dawn – Part 1 Soundtrack to be released later today.