"Nisei" is the ninth episode of the third season of the American science fiction television series The X-Files. It premiered on the Fox network on . It was directed by David Nutter, and written by Chris Carter, Frank Spotnitz and Howard Gordon. "Nisei" featured guest appearances by Steven Williams, Raymond J. Barry and Stephen McHattie. The episode helped explore the series' overarching mythology. "Nisei" earned a Nielsen household rating of 9.8, being watched by 16.36 million people in its initial broadcast. The episode received largely positive reviews from critics. The show centers on FBI special agents Fox Mulder (David Duchovny) and Dana Scully (Gillian Anderson) who work on cases linked to the paranormal, called X-Files. In this episode, Mulder and Scully investigate the origins of an alien autopsy Mulder believes is real. The investigation uncovers Japanese involvement and sees Mulder smuggle himself onto a secret cargo train to find out more. "Nisei" is a two-part episode, with the plot continuing in the next episode, "731". Inspired by the atrocities committed by Unit 731, a Japanese research program during World War II, "Nisei" was originally intended to be a stand-alone mythology episode, but was lengthened into two separate parts. The episode featured several scenes that required stunt work, which David Duchovny performed himself. The episode's title refers to the term nisei, meaning the son or daughter of an Issei couple born outside Japan. Plot In Knoxville, Tennessee, a mysterious train car is left in a rail yard. After dark, a group of Japanese scientists enter the car and conduct an autopsy on an alien body. The scene is recorded and transmitted via satellite. Suddenly, a strike team storms the car and kills the scientists, taking the alien corpse away in a body bag. Fox Mulder (David Duchovny) purchases an edited video of the autopsy. He believes the tape is authentic, but Dana Scully (Gillian Anderson) is skeptical. When the agents go to Allentown, Pennsylvania, to track down the distributor of the tape, they find him murdered. At the scene, they pursue and capture a Japanese man, Kazuo Sakurai, who is identified as a high-ranking diplomat. Walter Skinner appears and orders Sakurai released. Before doing so, Mulder searches his briefcase (which he did not turn in to the authorities) and finds both a list of Mutual UFO Network members and satellite images of a ship. The Lone Gunmen identify the ship as