| runtime = 93 minutes
| country = United Kingdom
| language = English
| budget = £1 million
| gross =
Inseminoid (titled Horror Planet in the United States) is a 1981 British science fiction horror film directed by Norman J. Warren and starring Judy Geeson, Robin Clarke and Stephanie Beacham, along with Victoria Tennant in one of her early film roles. The plot concerns a team of archaeologists and scientists who are excavating the ruins of an ancient civilisation on a distant planet. One of the women in the team (Geeson) is impregnated by an alien creature and taken over by a mysterious intelligence, driving her to murder her colleagues one by one and feed on them.
Inseminoid was written by Nick and Gloria Maley, a married couple who had been part of the special effects team on Warren's earlier film Satan's Slave. It was filmed between May and June 1980 on a budget of £1 million (£ million in ), half of which was supplied by the Shaw Brothers. The film was shot mostly on location at Chislehurst Caves in Kent as well as on the island of Gozo in Malta, combined with a week's filming at Lee International Studios in London. Composer John Scott completed the film's electronic musical score over recording sessions that lasted many hours.
Despite a good box office response in the UK and abroad, Inseminoid failed to impress most commentators, who criticised the effects and production design. The overall quality of the acting was also poorly received, although Geeson's performance was praised. Criticism was also directed at the premise involving an alien insemination, which some commentators saw as a weak imitation of Alien (1979). Both Warren and 20th Century Fox, distributor of Alien, rejected claims that Inseminoid was influenced by that film.
Plot
On a frozen planet in the future, a team of 12 Xeno Project archaeologists and scientists are excavating the ruins of an alien civilisation. They discover a cave system containing wall markings and crystals of unknown origin. During one of the surveys, a mysterious explosion cripples photographer Dean White and injures Ricky Williams. Deciphering the wall markings, exolinguist Mitch theorises that the civilisation was built on a concept of dualism: the planet orbits a binary star and seems to have been ruled by twins. Discovering that the crystals are surrounded by an energy field, Sharon, the medical assistant, suggests that the civilisation was controlled by a form of chemical intelligence.
Inside the team's base, one of the crystal samples begins to pulsate, causing the intelligence to take control of Ricky through a wound on his arm. In a delusional state, he is compelled to go back to the caves. After exiting the base, leaving the airlock's outer door open, he throws Gail into a pile of twisted metal, damaging her environmental suit and trapping her foot. Desperate to free herself, Gail removes her helmet and tries to amputate her foot with a chainsaw, but freezes to death in the planet's toxic atmosphere. Documentation officer Kate Carson shoots the returning Ricky with a harpoon gun before he opens the inner airlock door and evacuates all of the base's air.
Ricky and Gail are buried outside the base. Later, Mitch and Sandy return to the caves to collect more crystals. A monstrous alien creature appears and dismembers Mitch, then rapes Sandy with a transparent tubular phallus pumping green liquid. Sandy is taken back to the base and treated by the team's doctor, Karl, who discovers that the attack has triggered an accelerated pregnancy. When further underground explosions block off the caves, the survivors are left with nothing to do but wait for Xeno to pick them up.
The intelligence takes over Sandy, giving her superhuman strength. She stabs Barbra to death with a pair of scissors and mutilates Dean and the remains of Mitch, drinking their blood. The rest of the team take refuge in the control room as Sandy uses explosives to blow up the base transmitter. After Sandy appears to return to her normal self, Karl, Sharon and Commander Holly McKay try to sedate her. However, Sandy reverts to her violent state, killing Karl and Holly and disembowelling their corpses.
Mark radios Sandy to distract her while Kate and Gary leave the control room to arm themselves with chainsaws. Sandy uncovers the ruse and harpoons Gary outside the airlock, breathing the atmosphere to no ill effect as she kills him and feeds on his flesh. She then re-enters the base and gives birth to hybrid twins. Mark stumbles across the newborns and leaves them with Sharon as Sandy blows open the control room and smashes the equipment inside. She then uses another explosive charge to wound Kate, and kills her. Finally, Mark overpowers Sandy and strangles her to death with a cable. He returns to Sharon to find one of the twins drinking from her torn-out throat, then comes face to face with its sibling.
Twenty-eight days later, a Xeno shuttle lands on the planet to investigate the loss of contact with the team. With the base in ruins and all the occupants dead or missing, commandos Corin and Roy abandon the search for survivors and shuttle pilot Jeff radios Xeno for clearance to return. The final shots reveal that the twins have stowed away inside a storage compartment on board the shuttle.
Cast
Production
After making Satan's Slave (1976), Prey (1977) and Terror (1978), Norman J. Warren was to have directed a film called Gargoyles. After this production collapsed without a finished script, Warren and producer Richard Gordon took on a story idea from the husband-and-wife duo of Nick and Gloria Maley, who had supplied the special effects on Satan's Slave. Their script, which indicated that the film is set two decades in the future in a militaristic universe, was provisionally titled either Doom Seed or Doomseeds; this was changed to Inseminoid to avoid confusion with the 1977 film Demon Seed.
Gordon cast American actors Robin Clarke and Jennifer Ashley as Mark and Holly while on business in Hollywood.
The Shaw Brothers agreed to supply half of the proposed £1 million budget and became partners in the production, with elder brother Run Run Shaw being credited as the film's presenter in the title sequence.
Post-production
The film was brightened in post-production due to concerns that it would be harder to sell to television broadcasters if it looked too dimly lit. According to Warren, editor Peter Boyle "had a natural feel for the material and managed to create just the right pace and rhythm throughout the film."
Music
As the low budget precluded hiring an orchestra, Warren and composer John Scott agreed that the film should have an electronic score. The recording involved many hours of multitracking and overdubbing. Warren described the completed soundtrack as an "amazing achievement", noting that electronic scores were still "quite experimental" at the time.