Metaltron

"Metaltron" was the name given by Henry Van Statten to a Dalek soldier that fought in the Last Great Time War, and survived after falling through time to the Ascension Islands on Earth. Damaged, it passed through several collectors of alien technology, eventually becoming a living specimen in van Statten's Cage in 2012.

Biography
Before the end of the Time War, this Dalek fell through time and landed on the Ascension Islands circa 1962. Insane and screaming, it passed through several private collections in the 20th and 21st centuries. By 2012, it was in the possession of billionaire Henry van Statten, who kept it in the Vault. Having no other name for it, van Statten called it a "Metaltron". The "Metaltron" was kept locked in the Cage, restrained by tensile steel chains attached to stabilising pillars. He instructed another of his staff, Simmons, to make it talk. The last person to touch it without any gloves "burst into flames", at least according to what Simmons said. Although tortured, all it did was scream. With the intention of reaching other Daleks, it sent out a distress signal which was detected by the Ninth Doctor and Rose Tyler. Initially unaware of the source of the distress signal, the Doctor came to face-to-face with it. (TV: Dalek)

Having thought all of the Daleks destroyed (TV: The Day of the Doctor), he was shocked to find one alive. It moved its gun to exterminate the Doctor, but had insufficient power to do so. After a hostile and bitter discussion between them about the end of the Time War, the Doctor attempted to destroy the Dalek, pulling a lever which sent electricity through its casing. He was stopped by van Statten, who ordered two guards to "get him out", pulling the Doctor out the room. Simmons managed to turn the electricity off before the Dalek was destroyed. Henry van Statten was pleased to know what the "Metaltron" was really called.

Upon meeting Rose, who had not witnessed the exchange between the Dalek and the Doctor, it seemed to be a harmless victim. Rose, in an attempt to comfort it, touched the right part of the Dalek's dome (to the left of the eye stalk, from Rose's perspective). As she did so, it absorbed artron energy and DNA from her. It used this to regenerate itself and escape the Vault. It then downloaded all the data available on the Internet and killed Simmons, Bywater, De Maggio, and numerous others. It pursued both Rose and Adam Mitchell through the GeoComTex facility and killed 200 of van Statten's security.

However, the "Metaltron" found itself ultimately unable to kill Rose or van Statten. The human DNA that it had absorbed from Rose had brought with it emotions. Rose took the Dalek to the roof, where it blasted a hole in the ceiling and opened its battle armour to feel the sunlight. The Doctor then appeared, armed with an alien energy weapon, with the intent to kill the Dalek. Upon seeing it feel, the Doctor lowered the weapon at Rose's request.

Considering all the new emotions to be "sickness", the "Metaltron" asked Rose to order it to self-destruct, preferring death to a life with emotions. She refused at first, but eventually gave the order, and it destroyed itself. (TV: Dalek)

Legacy
This was the first time the Doctor had found a survivor of the Time War. Although he believed that this was the last Dalek, he would soon discover others. The Dalek Emperor himself survived, when his heavily-damaged flagship was flung through time before the time-lock occurred. (TV: The Parting of the Ways) Likewise, the four-member Cult of Skaro survived aboard their Void Ship, having in their possession a prison vessel loaded with millions of Daleks (TV: Army of Ghosts/Doomsday)

Rose would later recall her restoration of the "Metaltron" Dalek with her touch when the Cult of Skaro demanded that she open the Genesis Ark. She explained to Mickey Smith that the Dalek was broken and dying but when she touched it she brought it back to life, as the Daleks had evolved to use as a power supply the background radiation one "soaked up" from travelling through time in the TARDIS. (TV: Doomsday)

UNIT was aware of the "Metaltron", but lost track of it once it was relocated to the Vault. (AUDIO: The Dalek Transaction)

Personality
While it was a prisoner, the "Metaltron" refused to speak when Henry van Statten's staff were torturing it, although it did scream. It was enraged by the appearance of the Doctor and tried to exterminate him, but couldn't because its gun had been disabled. The Dalek demanded to be ordered what to do, ironically using orders itself in an attempt to receive them. However, it also begged for pity when the Doctor attempted to destroy it, despite the Doctor pointing out "you never did".

After absorbing Rose Tyler's DNA, the Dalek started feeling human emotions for the first time. Although it ruthlessly gunned down van Statten's staff, it was unable to kill Rose or van Statten. The Dalek then stated that it wanted freedom. As its personality had become more merciful than before, it hated itself, feeling that the emotions Rose had given it were making it weak. It eventually pled with Rose to order it to self-destruct, and she did so. (TV: Dalek)

Although not the first Dalek to kill itself, this Dalek was one of the few to do so out of self-hatred. (TV: Destiny of the Daleks, Revelation of the Daleks, Asylum of the Daleks)

This Dalek, as with all Daleks that originated from the Last Great Time War, possessed markings below its eyepiece to identify it. (TV: Dalek)

After hearing that this Dalek had burned in his crater for days, the Doctor believes it went insane. (TV: Dalek)

Behind the scenes

 * This Dalek also acts as the player character in the online game The Last Dalek. It presents an alternate version of the events of Dalek. In the game, the Dalek fights through the Vault, faces van Statten's forces and eventually the Doctor, who is exterminated by the Dalek. The game is completed when the Dalek finds and destroys the Doctor's TARDIS.
 * In The Day of the Doctor, as Gallifrey vanishes and the Dalek fleet is destroyed, one Dalek seems to survive as it spins off from the explosion. Although this would be consistent with the general backstory of the "Metaltron", there is no clear indication that it is the same Dalek.
 * Rusty, a Dalek captured by the Combined Galactic Resistance was similar to "Metaltron" in the sense that it is presented as a potentially moral Dalek. In the end, Rusty reformed, became good, and began operating alongside the Combined Galactic Resistance against the Daleks in the time of the New Dalek Paradigm.
 * Metaltron was adapted from a Dalek in the audio story Jubilee, on which Dalek was based.