Billie Eilish is rooting for the bad guy. In the first look at the Grammy winner's surprise acting debut on Prime Video's Swarm, a blonde-haired Billie, playing some kind of intense hypnotist, snaps her fingers and gets Dre (Dominique Fishback) to change her name back from someone named Kayla. Once that's accomplished, Billie's character says to her, "Tell me something you regret." That's when a montage of Dre performing all sorts of horrifying deeds – including wiping up a bloody crime scene – is shown. Looks like Dre might have more than something she regrets. Back in her office, Billie's character asks Dre, "Did you hurt someone?" When Dre responds with a yes, Billie's character smiles and says, "Very good." Premiering in March, Swarm – co-created by Donald Glover and Janine Nabers – follows Dre whose obsession with an international pop star forces her on a dark and twisted journey across the country. And Billie isn't the only star expected to make an appearance. The limited series will also feature Chloe Bailey, Paris Jackson, Rickey Thompson and Rory Culkin.