During one trip, he ends up stranded on the homely planet Lamuella, and decides to stay to become a sandwich maker for the local population.

Meanwhile, Ford Prefect has returned to the offices of the Hitchhiker's Guide, and is annoyed to find out the original publishing company, Megadodo Publications, has been taken over by InfiniDim Enterprises, which are run by the Vogons.

Ford expresses concern at the Guide's manipulation of events, noting its "Unfiltered Perception" and fearing its potence and ultimate objective.

Reporter Tricia McMillan is a version of Trillian living on an alternate Earth who never took Zaphod Beeblebrox's offer to travel in space.

However, due to damage to their ship in arriving, they have lost most of their computer core and their memories, with the only salvageable instructions being to observe something interesting with Earth.

The title derives from a joke early in the series, when Arthur Dent discovers that the entry for Earth in The Hitchhiker's Guide to the Galaxy consists, in its entirety, of the word "Harmless".

Ford had written an extensive entry covering life and recreation on Earth, but the Guide editors cut it back to "Harmless".

[2] The Independent concluded "Mostly Harmless has all the wit and inventiveness of vintage Douglas Adams, though its loose ends are not tied together as comprehensively as in previous Hitch-Hiker books".

[3] David Edelman in the Baltimore Evening Sun wrote: "Somewhere buried in the mess is a moral about learning how to feel at home in a chaotic universe.

During the ending, Ford explains that the dolphins got taught this skill from the Babel fish in exchange for knowing a good place to have parties.

All the major characters are carrying Babel fish in their ears, which rescue them at the moment of Earth's destruction by transporting them to the Restaurant at the End of the Universe.

In addition, the National Library Service for the Blind and Physically Handicapped released a version of the book, narrated by George Guidall-Shapiro, on 4-track cassette tape in 1993.