Species II (a.k.a Species 2: Offspring and Species 2: Origins) is a 1998 sequel to the 1995 film Species. It stars Natasha Henstridge, Michael Madsen and Marg Helgenberger, all of whom reprise their roles from the first film. It also features actor James Cromwell as "Senator Judson Ross".
Roughly two years after the events of Species, an American space mission lands on Mars, and collects soil samples. Back on board, the temperature on the ship thaws out frozen DNA in the soil samples, which then attempts to infect the astronauts. The mission safely returns to earth to universal cheering. Only Dr. Cromwell, a scientist and now an inmate in an asylum, reacts to their return with violent fits. After their return, the three astronauts are examined and quarantined not to engage in sexual intercourse for ten days. However, one of the astronauts - Patrick Ross - immediately disregards the advice and sleeps with two women that night. During intercourse, he begins to sprout tentacles. Both women undergo an accelerated pregnancy in which their stomachs split open like a flower and half-alien children emerge, killing them in the process. Patrick hides the rapidly growing alien children inside a remote shed and, the next day, tries to confide in his father, an ambitious U.S. Senator, who ignores his problems. Under military supervision, scientists led by Dr. Laura Baker have created a more docile clone of Sil, named Eve, in an effort to understand the alien life form and prepare for defense should it ever arrive on earth. During Patrick's sexual encounter, the isolated Eve - undergoing tests in the lab - shows signs of great physiological excitement. At the space center, Dr. Orinsky is working on the astronauts' blood samples and urgently tries to contact Dr. Cromwell, his former colleague. Afterwards, Patrick's blood sample falls to the floor and seeps into the wall. When Orinsky examines the strange puddle, an arm bursts out of the wall and disembowels Orinsky. The arm is then revealed to be that of Patrick, who has somehow snuck into the lab. Analysis of the corpse reveal the presence of alien DNA, similar to yet distinct from Eve's. Dr. Baker is reunited with Press Lennox to contain the threat. The two contact Cromwell, who explains that Mars was rendered uninhabitable by an alien species, and that he was institutionalized to silence his opposition to the Mars mission. With the quarantine about to expire, Press and Laura begin searching for the astronauts. They find astronaut Anne Sampas, who is also infected with alien DNA. Unfortunately, by the time they locate her, she has just had unprotected intercourse with her human husband and has become impregnated with another alien offspring. The tube-like creature emerges from Anne's womb and latches onto the husband's face, presumably suffocating him or feeding on his organs. Press and Laura then break into the bedroom and discover the alien. They shoot the creature and then gas it to death as it retracts back into Anne's body. Anne and her husband also die in the process. Dennis Gamble is located taken by government agents. Analysis of his blood reveal that he was not infected. Later on, he joins Press and Laura in their mission. After spending the night with his fiancé, Patrick wakes to find her mutilated body and another alien child. Horrified, he shoots himself along with the last trace of the human psyche within him. His head immediately regenerates and he displays immediate thoughts of reproduction. Patrick begins impregnating more women, mostly prostitutes, burying them next to his shed where he is accumulating a large family of alien children. At the lab, the scientists activate Eve's alien DNA to telepathically track Patrick. Eve traces Patrick, who is about to rape another woman. However, Patrick also locates Eve and, in order to get closer to her, gives himself up to Press and Dennis. As he enters the lab, Eve shows signs of being in heat. Patrick tries to enter her isolation cell but is chased off by Laura, Dennis and Press. Informed of his son's condition, Senator Ross refuses to be of help and instead meets Patrick at the shed. The two tearfully reconcile but Patrick's alien nature kills the Senator. Patrick helps his alien children to cocoon, awaiting their rebirth as adults. Meanwhile, Laura finds out that Dennis resisted infection due to his carrying a genetic flaw, and plans to infect the alien species with Dennis' DNA. As the team prepares, Eve breaks free from the lab to find Patrick. The team tails her, finds the shed and kills Patrick's brood. Eve and Patrick start to mate and transform into their alien forms, but are interrupted by Press. Alien-Patrick fights off Press and Dennis and also overpowers Alien-Eve (who attacked him at Laura's request), penetrating and killing her. Press stabs Alien-Patrick in the back with a pitchfork coated with Dennis' blood, causing Alien-Patrick to disintegrate. The military arrives and escort Press, Laura and the injured Dennis. Eve's lifeless human body is loaded into the back of an ambulance. As the vehicle departs, Eve's womb begins to swell, indicating an imminent birth. One of Patrick's children, who had not yet cocooned, looks on.