This is book six of three — Douglas Adams originally conceived The Hitchhiker’s Guide to the Galaxy as a trilogy, and then promptly went on to write two more books. Before his death he expressed a desire to write a sixth book in the series since he felt Mostly Harmless, the fifth book, ended on a fairly bleak note (no spoilers here, but I agree, although there’s nothing wrong with bleakness sometimes).
Sadly Adams died before writing the sixth book. A couple of years ago Eoin Colfer was commissioned to write the sixth book, And Another Thing… , with Adams’ widow, Jane Belson.
I reread the series this year and approached the sixth book with trepidation. I’m very wary about a new author taking up someone’s milieu in any context other than a homage. A new book in the actual series? Rarely works — see: Herbert, Brian. After finishing the novel, I have to say it’s a great read. It’s fun and it’s a worthy addition to the Hitchhiker world. If you’ve shared some of my reservations about this novel, I say give it an honest shot, and if you’ve never read any of the six, then get yourself a copy of book one — The Hitchhiker’s Guide to the Galaxy — and start reading.