If you were watched the Sunday, May 24 episode of BBC’s Killing Eve, you may have noticed a brand new cover of a familiar song, Taylor Swift’s “Look What You Made Me Do,†occurring during the episode. Swift, herself, was apparently such a big fan of the cover that she posted about it on social media. “VERY STOKED about this cover of lwymmd on @KillingEve by Jack leopards & the dolphin club!!†the pop star tweeted, before linking to the song. It didn’t take long for Swift’s fans to realize that Jack Leopards & the Dolphin Club was not a real band and that Swift may be back up to her ghostwriting ways. The stans got to the bottom of it, as stans are wont to do, and found out that the cover was credited to Jack Antonoff (a cowriter of the original) and Nils Sjöberg, the alias Swift used to pen Calvin Harris and Rihanna’s “This Is What You Came For.†Hot on the trail, the Swift sleuths followed more clues leading to the dominating theory that the male singer covering Swift’s Reputation track is none other than her brother, Austin Swift. Apparently, “The Dolphin Club†was a Twitter username Austin had once and the single’s cover art features a childhood photo of him. Wow, we really gotta get some Swifties into detective work. Check out Jack Leopards and The Dolphin Club’s cover of his sister’s recording artist Taylor Swift’s “Look What You Made Me Do.â€