Taylor Swift’s “Bad Blood” video is causing quite the internet stir. The 25-year-old singer’s “Sin City”-inspired short film is full of Hollywood starlets, models and talented musicians. Not sure when to catch Swift’s video? Here’s everything you need to know:

When: The video will premiere ahead of the Billboard Music Awards this Sunday. The show will kick off at 8 p.m. EDT on ABC.

Where: The Billboard Music Awards are being filmed at the MGM Grand Garden Arena in Las Vegas and will be hosted by Chrissy Teigen and Ludacris. 

What: "Bad Blood" is directed by Joseph Kahn, who also directed Swift’s video for “Blank Space.”

Who: Former Victoria’s Secret model and best friend of Taylor Swift Karlie Kloss just joined the music video’s cast on Monday. Kloss is the latest of an already star-studded lineup that will include Paramore lead singer Hayley Williams, Kendrick Lamar, actress Lena Dunham and Victoria’s Secret model Lily Aldridge. Songstress Ellie Goulding, actress Zendaya, model Gigi Hadid and actress Hailee Steinfeld will also make appearances in the video. Each has an alter ego, and Swift herself will play “Catastrophe.”

Why: Swift hasn't confirmed anything, but the song is rumored to be about her former friendship with fellow pop artist Katy Perry. Both have dated John Mayer, and there are rumors of a feud that involved stealing one another's backup dancers.

"For years, I was never sure if we were friends or not," she told Rolling Stone last September of Perry. "She would come up to me at awards shows and say something and walk away and I would think, 'Are we friends, or did she just give me the harshest insult of my life?'" Swift added that now the two are "just straight-up enemies."