This Week in USA
![USA](https://layout.doctorwhonews.net/img/flags/US.gif)
The Ribos Operation: Part Four
Last updated 02 January 2017
8:30pm-9:00pm EST (01:30 GMT) < > « »
![Premiere](/images/premier.gif)
Retro TV
![Google](http://www.google.com/calendar/images/ext/gc_button1_en-GB.gif)
Featuring: Tom Baker, John Leeson, Mary Tamm, Iain Cuthbertson
Pursued into the catacombs by the Graff and attacked by the ferocious Shrivenzale, the Doctor and Romana struggle to stay alive and find the first segment of the Key to Time.
Synopsis Source: Doctor Who Guide
Broadcast Source: Retro TV