The Ribos Operation is the first serial of the 16th season of the British science fiction television series Doctor Who, which was first broadcast in four weekly parts on BBC1 from 2 to 23 September 1978.
In the serial, the exiled Emperor of Levithia, Graff Vynda-K (Paul Seed), seeks a piece of the rare element jethrik on the planet.
The White Guardian recruits the Fourth Doctor to collect the six hidden and disguised segments of the powerful Key to Time.
The Graff Vynda-K provides a large sum of money as a deposit for the planet that is to be kept safely in the room with the crown jewels, watched by Ribos guards by day and a shrivenzale beast by night.
Garron and Unstoffe claim the Graff's deserted ship, full of years of plunder, while the Doctor and Romana transform the jethrik into the first piece of the Key to Time.
[5] Bahn wrote of the Graff Vynda-K that he was "a perfect mark for a con-job story—dour and humorless and eager to use violence where it’s probably not even necessary, it’s easy to feel like he deserves to be rooked".
[4] The character of Garron was intended to be Australian-hence the references to Australia such as the statement that he swindled investors by fraudulently selling the Sydney Opera House-but was changed to being English when Iain Cuthbertson won the part in an audition.
[8][9] Elisabeth Sladen, who as Sarah Jane Smith was last seen in The Hand of Fear (1976), was approached to return to the series as a replacement for Leela (who had left in The Invasion of Time).
Paul Cornell, Martin Day, and Keith Topping gave the serial a favourable review in The Discontinuity Guide (1995), calling it "a lovely story".
[11] In The Television Companion (1998), David J. Howe and Stephen James Walker praised the "cracking set of scripts" and production values.
Club reviewer Christopher Bahn called The Ribos Operation one of Robert Holmes' better stories, writing that it was "a fun, tightly constructed caper".
John Leeson, who provided the voice of K9 in the original 1978 TV serial, reads Ian Marter's complete and unabridged novelisation of this story.
Along with the rest of season sixteen, it was released in North America as part of the Key to Time box set, as well as being marketed separately.