Douglas Adams (Hitchhiker's Guide to the Galaxy) penned this episode in which the Doctor and Romana seek the second segment of the Key to Time on a parasitic planet.
Hitchhiker's Guide to the Galaxy
scribe Douglas Adams made his scriptwriting debut for Doctor Who with this 16th-season episode, the second in the "Key to Time" story arc, and a delight for fans of the series and Adams's work. Tom Baker's Doctor and companion Romana (Mary Tamm), in pursuit of the second segment of the Key to Time, accidentally land on the planet Zanak, which has been cored out and converted into a ship with which to plunder the mineral resources of other neighboring planets. The Doctor and Romana must outwit the Captain, the planet's half-human, half-metal ruler, in order to retrieve the segment, which is concealed in the shriveled husk of a conquered planet. Adams's wry humor (well delivered by Baker and Tamm) and imaginative flourishes help buoy this episode, though Who
aficionados that dislike the series' humorous efforts may not appreciate the serial's overall light tone. Fans of the Hitchhiker
series will note several references to elements from that series (Adams was writing a radio adaptation of Hitchhiker's Guide
at the same time he wrote this episode) woven throughout the script. --Paul Gaita