So Long, and Thanks for All the Fish

So Long, and Thanks for All the Fish is a humorous science fiction novel by Douglas Adams, first published in 1984, and the fourth book in The Hitchhiker's Guide to the Galaxy series. It stays in Adams's familiar universe of strange ideas, dry wit, and a playful approach to science fiction. The title comes from the message left by the dolphins when they left Earth.

This book will suit readers who already enjoy Adams's tone, and anyone looking for science fiction that is funny without being loud or heavy. It works well if you want something quick on its feet, with a mix of everyday absurdity, sharp dialogue, and a loose, imaginative connection to technology and culture. It fits naturally with comic and satirical science fiction.