Inseminoid

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.