The Salmon of Doubt was originally intended to be a
Dirk Gently novel. The plot, set a few weeks after the events in
The Long Dark Tea-Time of the Soul, involves Dirk Gently refusing to help find the missing half of a cat, receiving large amounts of money from an unknown client, and then flying to the United States. Dirk pays a visit to Kate Schechter (who had first appeared in
The Long Dark Tea-Time of the Soul) and tells her that prior to the potential client, he had been so bored that he had started a habit of dialling his own phone number and discovered he'd answered his own calls. A faxed summary reprinted before the text mentions travelling "through the nasal membranes of a
rhinoceros, to a distant future dominated by estate agents and heavily armed kangaroos." The version in the published book was described as the strongest content from several unfinished drafts that were written.
Later intention Adams said that while he originally planned on writing a third Dirk Gently book, the ideas which he had for it would have fitted 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." He had expressed dissatisfaction with the fifth
Hitchhiker book,
Mostly Harmless, saying "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." ==Published version==