Underworld is the fifth serial of the 15th season of the British science fiction television series Doctor Who, which was first broadcast in four weekly parts on BBC1 from 7 to 28 January 1978.
The Minyan civilisation retained some Time Lord gifts, including cellular rejuvenation and the use of pacifier guns to alter the mental state of the aggressor.
Their aim is to find the missing ship, the P7E, which disappeared en route to Minyos II while carrying the genetic race banks of the entire species.
The Doctor and Leela encounter Idas, a young man nearly killed in a Skyfall, learning how the local population is managed and terrorised.
Idas takes advantage of the situation to round up the other Trogs and lead them to the safety of the R1C, while the Doctor engineers the return of the fission grenades to the Oracle.
With moments to spare, the R1C blasts away, loaded with the slaves and the race banks, and is pushed outward from the planetoid by the explosion of the fission grenades.
References include the "Minyan" race (related to the Minoans), the search for "P7E" (Persephone), and character names such as Jackson ("Jason"), Orfe ("Orpheus"), Herrick ("Heracles"), Tala ("Talaus"), Idmon and Idas.
[4] Paul Cornell, Martin Day, and Keith Topping wrote of the serial in The Discontinuity Guide (1995), "The direction is a bit lazy, and the design could be better ...
"[6] In The Television Companion (1998), David J. Howe and Stephen James Walker noted the bad reputation the serial had, but felt that it was better than that and a good example of the era.
[7] In 2010, Patrick Mulkern of Radio Times panned the story and its "vapid characterisation, dodgy science and a dearth of anything dramatically engaging".
[1] A novelisation of this serial, written by Terrance Dicks, was published by Target Books in January 1980 under the title Doctor Who and the Underworld.