Duplication machine

By the aftermath of the Dalek-Movellan War, the Daleks had developed a duplication machine that could display the memories of a given subject on a monitor and create a copy of their mind to be implanted into a Dalek duplicate. (TV: Resurrection of the Daleks) Scrutinising Dalek history, the Time Lords observed that the duplication machine and the earlier interrogation machine was a refined version of the earlier Mind Analysis Machine. (PROSE: Dalek Combat Training Manual)

By one account, the Daleks' use of duplicates was a recent development in the Dalek-Movellan War, in the aftermath of the Movellan Incident, which did not exist during their earlier conflict with the Space Security Service. (AUDIO: The Dalek Defence)

A duplication machine was contained within a designated duplication room aboard the Supreme Dalek's Battlecruiser during the Duplicate Incident. Intending to create a duplicate of the Fifth Doctor to assassinate the High Council of Time Lords on Gallifrey, the Daleks apprehended him and brought him to the duplication chamber where his mind was subjected to the machine. During the ordeal, the monitor displayed images of the Doctor's previous incarnations as well as his present and past companions: Vislor Turlough, Tegan Jovanka, Nyssa of Traken, Adric, Romana II, Romana I, K9, Harry Sullivan, the Fourth Doctor, Sarah Jane Smith, Jo Grant, the Brigadier, Liz Shaw, the Third Doctor, Zoe Heriot, Victoria Waterfield, Jamie McCrimmon, the Second Doctor, Ben Jackson, Polly Wright, Dodo Chaplet, Sara Kingdom, Katarina, Steven Taylor, Vicki Pallister, Barbara Wright, Ian Chesterton, Susan Foreman and the First Doctor. Ultimately, the process was stopped by Stien, a defective Dalek duplicate. (TV: Resurrection of the Daleks)

Behind the scenes

 * During the mind analysis scene, Leela and Kamelion are the only companions not to appear in the flashback sequence; a clip of the former, taken from TV: The Face of Evil was to be featured during the aforementioned flashback sequence, but was omitted by mistake. Of the companions seen, six never encountered the Daleks on-screen: Dodo, Zoe, Liz, Romana I, Adric, and Nyssa.