Mostly Harmless - Continuation and Sixth Book

Continuation and Sixth Book

In an interview reprinted in The Salmon of Doubt, Adams expressed dissatisfaction with the "rather bleak" tone of this book: "People have said, quite rightly, that Mostly Harmless is a very bleak book. And it was a bleak book. I would love to finish Hitchhiker on a slightly more upbeat note, so five seems to be a wrong kind of number; six is a better kind of number."

For the downbeat tone of the novel, Adams blamed personal problems, saying "for all sorts of personal reasons I don't want to go into, I just had a thoroughly miserable year, and I was trying to write a book against that background. And, guess what, it was a rather bleak book!"

When Adams died on 11 May 2001, it seemed that Mostly Harmless would become the final book of what Adams called a "trilogy". The Salmon of Doubt was published posthumously, containing, alongside numerous articles written by Adams, several chapters belonging to a new storyline for a third "Dirk Gently" novel. In interviews that can be found in The Salmon of Doubt, Adams admitted that while he was planning on writing a third Dirk Gently book, the ideas he was having for it would have fit better into another Hitchhiker's book: "A lot of the stuff which was originally in The Salmon of Doubt really wasn't working", and he planned on "salvaging some of the ideas that I couldn't make work in a Dirk Gently framework and putting them in a Hitchhiker framework... and for old time's sake I may call it The Salmon of Doubt."

Although the complete destruction of every version of the Earth in every possible timeline, along with the death of nearly all the regular characters, would seem to make a continuation extremely unlikely, Adams had remarked that the afterlife-enhanced state of the regulars merely meant he would not have to waste time at the beginning of the next book gathering them together or explaining what they'd been up to in the intervening period.

On 16 September 2008, it was announced that a sixth book would be written, by Artemis Fowl author Eoin Colfer, with the support of Adams's estate. And Another Thing... was released on 12 October 2009 (the thirtieth anniversary of the first book) in hardback by Penguin Books in the UK, and by Hyperion Books in the U.S.