Creature

Two geologists from NTI uncover an ancient alien laboratory on Titan. Inside sits an egg-like container that appears to preserve an extraterrestrial organism. The discovery sets the stage for what will come next.

From the egg, an alien life-form emerges and attacks the two geologists. Both are killed in the lab, leaving the site deserted and dangerous. The immediate threat of the creature is established.

Two months after Titan, the geologists' ship collides with the space station Concorde in orbit around Earth's Moon. The crash results in the death of the pilot and leaves both ships damaged. The incident draws NTI's attention and prompts a rescue mission.

NTI orders the Shenandoah to travel to Titan to study or contain the alien threat. The crew includes Captain Mike Davison, Susan Delambre, Jon Fennel, Dr. Wendy Oliver, David Perkins, Beth Sladen, and security officer Melanie Bryce. The mission is framed as a rescue and containment operation.

While in orbit, the Shenandoah picks up a distress signal from the rival West German Richter Dynamics ship. The crew prepares for possible contact or rescue actions. The signal hints at shared stakes with the German vessel.

A ground collapse during descent drops the Shenandoah into a cavern on Titan and wrecks the ship. Radio communication fails, complicating the rescue and exploration. A search party is dispatched to contact the German ship.

On the German ship, the crew's eggs and cadavers are found; the creature emerges and kills Delambre who lingers behind. Fennel goes into shock at the horror, while Bryce sedates him to keep the plan afloat. The Germans reveal their ship's crews were slain by the creature.

Hans Rudy Hofner secretly sneaks aboard the Shenandoah, claiming his crew was slain by the creature. He suggests returning to his ship to fetch explosives, but the Americans refuse to take that risk. The tension between cooperation and caution heightens.

Unsupervised in the medbay, Fennel witnesses an undead Delambre through a porthole. She lures him outside and, after removing his helmet, she asphyxiates him and attaches an alien parasite to his head. Now under the creature's control, Fennel broadcasts a summons inviting the others to the German ship.

Hofner and Bryce are sent to retrieve air tanks for Shenandoah and to guard the ship while the others go to the Richter vessel. The plan divides the crew and increases the risk as the alien presence spreads. In the meantime, Fennel's parasitic control covertly guides the moves.

On their route, Hofner and Bryce pass by the ship's menagerie and are attacked by a version of Delambre. The encounter confirms that the creature controls its victims as biological puppets. The danger escalates as the crew realizes the threat is inside their own ship.

Davison insists that medical officer Oliver examine Fennel's head. Fennel, now controlled, is to be fed to the creature in engineering. Oliver is killed when the creature decapitates her; Perkins shoots and kills Fennel by blasting his head to end the threat.

Sladen is attacked by Hofner after becoming infected and escapes the ship, forgetting to wear her helmet. Perkins spots her outside and opens the airlock, sending her unconscious back inside carried by Hofner to lure the others. Davison confronts Hofner and tears off the parasite, ending his immediate threat.

The survivors formulate a plan to electrocute the creature using the ship's fusion modules, which require access through the engineering quarters. Sladen and Davison construct the electro trap while Perkins monitors the creature from the computer room. Alarms sound as the creature sabotages the ship in its advance.

The creature captures Sladen inside engineering, forcing a tense chase. Perkins lures the creature away and attaches a bomb to buy time; Davison jets the bomb out through the airlock. Bryce shoots the baited creature to ignite the explosion, killing it. The three survivors recover, and they depart Titan aboard the West German ship.