I'm obsessed with the myth of the Changeling, a myth used to explain & stigmatise disabled children, the belief is that if your child was chronically sick or "imbecilic" it had been swapped out by a troll, goblin or mean spirited fairy of some kind while you were sleeping. people literally killed children and family members over this in the 1700's. A spirit double is a similar myth but one used to describe feeling alien to yourself. I remember working on the track and thinking about how disconnected i am from me, how the world had made me feel like a changeling, like i have this infinite & inhuman meanness in my sickly heart. i'd been a fan of Eilish's for a while & we started following each other on twitter so i hit her up. Eilish also new about changelings and spirit doubles & felt close to the myth so she was a perfect fit for the song."