The Hitchhiker's Guide to the Galaxy Tertiary to Quintessential Phases

The Tertiary Phase, Quandary Phase and Quintessential Phase are respectively the third, fourth and fifth series of The Hitchhiker's Guide to the Galaxy radio series. Produced in 2003 and 2004 by Above the Title Productions for BBC Radio 4, they are radio adaptations of the third, fourth, and fifth books in Douglas Adams' The Hitchhiker's Guide to the Galaxy series: Life, the Universe and Everything; So Long, and Thanks For All the Fish; and Mostly Harmless.

These radio series consisted of a total of fourteen episodes, following on from the twelve episodes from the original two series (the Primary and Secondary Phases) which originally aired in 1978 and 1980.

The producers chose not to continue the ordinal sequence established by the Primary, Secondary and Tertiary phases. If they had done so, the fourth and fifth series would have been termed quaternary and quinary. Humorously, they chose "Quandary," which means "dilemma," and "Quintessential," which today means "the most perfect example of something," although the original meaning of quintessential was "fifth element."

The Hitchhiker's Guide to the Galaxy: Tertiary Phase, based on Life, the Universe and Everything, ran on BBC Radio 4 from Tuesday 21 September to 26 October 2004, with repeats on the following Thursdays. Episodes were subtitled "Fit the Thirteenth" through "Fit the Eighteenth". The third novel was adapted by Dirk Maggs, John Langdon and Bruce Hyman following instructions left by Adams.

Most of the original radio series cast returned, with the exception of three, due to their deaths: Richard Vernon (died 1997) as Slartibartfast, replaced by Richard Griffiths; Peter Jones (died 2000), replaced by his friend William Franklyn, with some brief excerpts from Jones' original narration used in Fit the Thirteenth of the radio series disguised as the Book's speech-generation system changing as part of updates to the Guide from the publisher; David Tate (died 1996), who played a multitude of minor roles in the two original radio series including Eddie, the Heart of Gold's computer.Bill Wallis, who played the roles of Mr Prosser and Prostetnic Vogon Jeltz in the original series, was not available. Toby Longworth took the role of Jeltz in the new series. On the other hand, John Marsh, who was the original series' continuity announcer, returned to announce the credits. There was even a cameo role by Adams himself (who had died in 2001) as Agrajag, edited from his BBC audiobook recording of the novel.

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