A vicious creature escapes its crate and kills two crewmen on a Chinese freighter before it docks in California. A man named Dr. Ian Detweiler is angry that he hasn't been notified of the creature's arrival, and also the fact that it's gone. The wolf-like beast goes on to slaughter a customs agent and his dog. Mulder and Scully find that Detweiler is a cryptozoolgist, and that he thinks the creature has been stolen. Mulder suspects the dog has human-like intelligence, and goes to a dog expert named Karin Berquist who he's become acquainted with through the Internet. Berquist even has her own "I Want To Believe" poster, and Scully quickly thinks that she's more interested in Mulder than the case.
Berquist is dismissive of the idea that the beast is an extinct dog called a Wanshang Dhole. A Fish and Game officer observes a human figure change into the wolf beast before it attacks him. Berquist becomes more interested in the case, and also says she distrusts Detweiler. A vet manages to escape the beast and trap it in a room, but responding officers end up shooting a St. Bernard by mistake. After patching the dog up, the vet is killed and the dog transforms into the beast and runs off.
Berquist says that if the Wanshang Dhole survived it was because it was more cunning than man, and doesn't think Detweiler would have been able to catch it. Mulder begins to suspect Detweiler of something after finding that he stopped by the dead vet's clinic to pick up tranquilizers. He accuses Detweiler of getting caught by the Wanshang Dhole himself, and now becomes a shapeshifter upon nightfall and unsuccessfully sought to fight it with the tranks. Berquist confirms that Detweiler is the beast, and that he needs to be killed. She also tells Mulder that he'll try to kill a Fish and Game officer he wounded but didn't kill.
Detweiler doesn't show up at the hospital, and Mulder realizes that Berquist lied to him. Berquist waits in her home for the Detweiler-beast with a tranquilizer gun, but ends up letting him attack her. As a result, she gets pummeled through a second-story window. Detweiler is killed after being impaled on a fence, but Berquist also dies. She's also sent Mulder her poster, and he puts it up to replace the one destroyed in the fire.
Andrew Robinson, as Detweiler, also played Garak on Star Trek: Deep Space Nine. Melinda Culea, who plays Karin Berquist, was in several episodes of The A-Team as Amy Allen.
Episode Body Count
Fong and Woo: thanks for everything, signed, Detweiler/Alpha's teeth.
JoJo: who the hell is evil enough to kill a golden retriever? Oh right, Detweiler/Alpha.
Jake Conroy: a customs agent killed by Detweiler/Alpha.
Frank Fiedler: a Fish and Game officer killed by Detweiler/Alpha.
Dr. James Riley: a veterinarian who has his throat torn out by Betweiler/Alpha.
Dr. Ian Detweiler/Alpha: impales himself on a fence after attacking Berquist and flying through a window. I'll count it as a creature death, since he was in dog form when he died.
Karin Berquist: dies after being attacked by Detwiler/Alpha.
Cumulative Body Count (133/202 episodes, 1/2 movies)
Humans: 1,534Creatures: 104
Grand Total: 1,700