At an unspecified time, The Doctor (Tom Baker) and staunch companion Sarah Jane Smith (Elizabeth Sladen) unexpectedly find themselves in the planet Karn, diverted there for an unstated purpose by the Timelords, but the Doctor is certain that he has been brought there to do some "dirty work" for his overlords, a hunch that proves right. The landscape it littered with crashed spaceships from dozens of worlds, but no survivors are evident. It turns out that the lack of survivors is due to them being killed and their body parts harvested by Condo (Colin Fay), the hulking dimwitted slave/assistant to Dr. Solon (Philip Madoc), a madman who was once considered the galaxy's greatest surgeon. He is obsessed with crafting a viable body for the evil Timelord Morbius, of whom all that remains is his sentient brain in a life-sustaining tank, ands all he needs is a suitable head. The Doctor's curly-topped noggin happens to be both a perfect match in terms of species and also convenient, but while fending off the machinations of Solon, the Doctor must put a stop to the threat of Morbius before he is resurrected, he must also prevent the Sisterhood of Karn — basically a cabal of science-fictional witches — from sentencing him to death, as they are convinced that he has been sent by the Timelords to steal the sacred flame that grants them near-immortality.
The Sisterhood of Karn gets its chant on.
During this era of DOCTOR WHO'S classic 1970's run, the program, which had initially been conceived as a means by which to educate children about history, truly found its groove (and immense popularity and relevance withing its native British culture) once it began exploring its conceit of being able to have its protagonist and his companions freely travel throughout the boundless reaches of time and space, where they often ran afoul of assorted evil life forms that could be categorized as "monsters," though always with a scientific/biological explanation for their existence.
By the mid-1970's, the children that had watched DOCTOR WHO since its debut in 1963 had grown up with the program, and it's more kiddie-oriented aspects began to wane as the show hit its adolescence at the same time as its audience. The stories became darker and were front-loaded with elements that kept its fans terrified, with a common experiential marker of British youth of the era being "watching DOCTOR WHO from behind the setee." Though still often quite shonky thanks to the BBC's notoriously tight-fisted budgets, the series more than compensated for its lack of funds with scary scripts and solid performances from the cast.
Once under the control of
producer Philip Hinchcliffe and with actor Tom Baker taking over as the
Fourth Doctor, becoming arguably the most iconic actor to essay the role
as of this writing, the stories embarked on a two-year (1975-1977)
streak of serials that went as far as possible in providing scares
allowable under the auspices of the BBC's censors, material that would
set DOCTOR WHO firmly in the sights of hardline Christian conservative
Mary Whitehouse, an opponent to what she considered changes to
"traditional" British values, and self-appointed arbiter of good taste
and decency in media.
While wielding no officially appointed position for weighing in on such matters, damned near any aspect of change that began during the 1960's, be it the sexual revolution and feminism, hit records like Alice Cooper's "School's Out" and Chuck Berry's cover of Dave Bartholomew's "My Ding-a-Ling," sitcom TILL DEATH US DO PART (upon which ALL IN THE FAMILY was based), and THE BENNY HILL SHOW (for obvious reasons), were vehemently opposed by Whitehouse, so it was only a matter of time before the BBC would pussy-out and cave to Whitehouse's criticisms, toning down the material to an insulting degree in the name of children, but in actuality to serve her own ultra-conservative agenda. Fortunately, "The Brain of Morbius" went out before Whitehouse's baleful influence would neuter DOCTOR WHO for the remainder of its original run.
Brain of Morbius" is of interest to horror buffs because it is
unabashedly meant to evoke the look and feel of Hammer films, the flavor
that dominated U.K. horror for almost two decades at the time of its
airing. It has all of the elements of a Hammer Frankenstein entry,
including mad scientist, hulking lab assistant of questionable
intelligence, an atmospheric landscape, an moody lab stocked with all
manner of bubbling vials and sparking electrical ephemera, and, of
course, a creature crudely assembled from whatever body parts were
available, in this case items savagely stolen from murdered survivors of
crash-landings on Karn.
The Morbius creature is a piecemeal horror of mismatched biological elements — a hulking, hairy body, one arm a massive crustacean claw while the other is the flesh and bone of a human, surmounted with a bubble sporting artificial eye stalks — and it must have been terrifying to younger viewers at the time. Hell, it's still unnerving, with its threadbare look actually adding to its effectiveness.
In short, "The Brain of Morbius" is simply an old school family-friendly creature feature of the type made for saving an otherwise boring Saturday afternoon, and it's also probably the closest that classic DOCTOR WHO got to crafting a straight-up horror yarn (science-fictional aspects notwithstanding).