Katabasis is a 2025 fantasy novel by American writer R. F. Kuang. It was released on August 26, 2025. The novel follows two magicians, doctoral candidates, who must venture into hell to save their thesis advisor in order to receive letters of recommendation. No. 1 on The New York Times Fiction best seller list for 1 week, from the issue of September 14, 2025 (Harper Voyager). Wiki link