In a previous interview, Mars promised "It Will Rain" would be "dark," and he didn't lie.The track — co-written and co-produced by Mars' team, the Smeezingtons — is signature Mars: Sweeping and romantic, it focuses on the power of true love and the emotional pain of heartbreak. The pain of the track is reminiscent of his smash "Grenade."


" 'Cause there'll be no more sunlight, if I lose you, baby," he sings on the emotional chorus. "There'll be no clear skies, if I lose you, baby/ Just let the clouds, my eyes will do the same if you walk away/ Every day, it will rain."


"The Twilight Saga: Breaking Dawn - Part 1" opens in theaters November 18. "After seeing the movie, I thought that it would be a perfect fit," Mars said of the song. "The 'Twilight' movies for me [are] a love story. But it's a dark love story," he added. "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."


On Monday, a full track list dropped, revealing which other artists made the final cut for the November release. Christina Perri, Theophilus London and Aqualung & Lucy Schwartz are a few of the artists who will be featured. The track list also reveals that Iron & Wine's song "Flightless Bird, American Mouth (Wedding Version)" will be played during the long-awaited wedding.

The full track list for "The Twilight Saga: Breaking Dawn - Part 1" soundtrack:

» The Joy Formidable, "Endtapes"
» Angus & Julia Stone, "Love Will Take You"
» Bruno Mars, "It Will Rain"
» Sleeping at Last, "Turning Page"
» The Features, "From Now On"
» Christina Perri, "A Thousand Years"
» Theophilus London, "Neighbors"
» The Belle Brigade, "I Didn't Mean It"
» Noisettes, "Sister Rosetta (2011 Version)" 
» Cider Sky, "Northern Lights"
» Iron & Wine, "Flightless Bird, American Mouth (Wedding Version)" 
» Imperial Mammoth, "Requiem on Water"
» Aqualung & Lucy Schwartz, "Cold"
» Mia Maestro, "Llovera"
» Carter Burwell, "Love Death Rebirth"

Check out everything we've got on "The Twilight Saga: Breaking Dawn - Part 1."