The Long Dark Tea-Time of the Soul is a 1988 humorous fantasy detective novel by Douglas Adams. It is the second book by Adams featuring private detective Dirk Gently, the first being [Dirk Gently's Holistic Detective Agency](https://openlibrary.org/works/OL2163714W). It was followed by the [Salmon of Doubt](https://openlibrary.org/works/OL2163715W), an incomplete Dirk Gently novel included in a posthumous collection of the same name. The Long Dark Tea-Time of the Soul has been adapted for radio, and several plot lines appear in the 2010 BBC TV series.