That could have been me.
If “The Leisure Hive” signals new producer John Nathan-Turner’s intention to change Doctor Who into a snappier and more modern show, “Meglos” (Series Production Code 5Q), by series newcomers John Flanagan and Andrew McCulloch, takes the transformation to its logical extreme, nearly writing the Doctor out of his own series. By the time filming commenced on “Meglos,” out of broadcast order mid-way through the Season Eighteen production block, Tom Baker’s departure was all but confirmed, and though the shocking lack of focus on the Doctor in the story was likely coincidental, given the neophytes behind the script, it demonstrates Nathan-Turner comfortability sweeping away as much of his predecessors’ legacy as possible, star included.
Which is not to say that “Meglos” lacks focus on Tom Baker, who gets to play both the Fourth Doctor and a cactus.
Indeed, it is Baker’s double billing as the Doctor and as the title character, Meglos, the last survivor of the desert planet Zolfa-Thura (and, yes, a cactus), that enables him to claim as much of the screen as he does against a wide range of guest stars who hold court in their own right, most notably Jacqueline Hill, returning to Doctor Who some fifteen years after last appearance as Barbara in “The Chase.” She features as Lexa, high priestess of Ti, who oversees the Dodecahedron, a mysterious ten-sided stone worshipped by the Tigellans living beneath the surface of their planet, located in the same solar system as Zolfa-Thura.
The Dodecahedron serves as the MacGuffin in the story, a boulder-sized polyhedron of unknown provenance providing all the energy needed to maintain the underground city. The Tigellan Savants harness its power but are not allowed to examine it, as the servants of Ti believe it to be a gift from their god. Its energy output has been fluctuating, though, so Zastor (Edward Underdown), the nominal leader of Tigella, invites the Doctor—conveniently an old friend who just happens to be in the right spatial and temporal neighborhood—to help solve the problem.
Simultaneously, Meglos has summoned a band of interstellar freebooters led by General Grugger (Bill Fraser) and Lieutenant Brotadac (Frederick Treves) to his lair beneath the Screens of Zolfa-Thura, a set of pentagonal metal barriers that are the sole surviving structures on the long-abandoned planet. They have been tasked with providing an “earthling” (Christopher Owen) for the cactus to transfer his essence into, legs apparently providing more mobility than a planter. Armed with appendages, Meglos sets about with his real goal of purloining the Dodecahedron, which turns out to be a power source created on Zolfa-Thura some ten thousand years prior and capable of producing enough energy to vaporize planets when properly harnessed. And to gain access to the Tigellan city, all Meglos needs to do is get the real Doctor out of the way and impersonate him, assuming no one notices the spines…