Callie Hart is a British author of romance and fantasy fiction. She is best known for her Fae & Alchemy series. Her novel Quicksilver (2024) became a #1 New York Times and Sunday Times bestseller. The novel became a BookTok phenomenon and is set to be adapted for film by Netflix. No. 1 on The New York Times Fiction best seller list for 1 week, from the issue of September 7, 2025 (Forever). Wiki link