television programme. Unlike other Daleks the four members of the Cult have individual names; Sec, Thay, Jast and Caan. While Daleks Thay, Jast and Caan appear identical to other Daleks, Dalek Sec is distinguished by a black casing. The Cult are shown to possess a sense of individuality and the ability to initiate an "emergency temporal shift" to escape danger by travelling through time and space. In "Doomsday" a combination of three plungers are used to extract information from a person's mind with lethal results (although it is implied that this can be done without killing the victim). In the episode "Daleks in Manhattan" (2007) the plungers of the Cult of Skaro Daleks are used to detect the intelligence of human subjects, and in one scene a plunger is temporarily replaced by a syringe-like device. The BBC book Doctor Who Files: The Cult of Skaro states that Dalek Sec's black casing is constructed from "Metalert", an enhanced form of Dalekanium reinforced with flidor gold and sap from the extinct Arkellis flower. This fictional material and its constituents have their origins in the TV Century 21 Dalek comic strip from 1965, where they are mentioned in the stories Duel of the Daleks and Genesis of Evil. Vault Daleks Appearing in the linked episodes "The Stolen Earth" (2008) and "Journey's End" (2008), Vault Daleks watch over Davros in the Vault of The Crucible space station, acting as both bodyguards and warders. Although unnamed during the episodes in which they appear, the term is used for the variant on the BBC's Doctor Who website. Character Options named its licensed scale toys of the variant "Crucible Daleks". Vault Daleks form part of the recreated Dalek race each of which, Davros states, has been genetically engineered with cells taken from his own body. Instead of the standard plunger they are fitted with a claw-like appendage incorporating eight "pincers", which are shown to fit directly into some of the ship's controls. Death Squad Daleks In the episode "Revolution of the Daleks", Death Squad Daleks are introduced. According to the episode's narrative, they are enforcers of the Dalek race's purity through the destruction of any Daleks which are considered to be genetically corrupt. These Daleks are visually distinguished by having their plunger replaced by a five-pincered claw, similar in design to that fitted to Reconnaissance Scout Daleks and Defence Drone Daleks. Executioner Daleks New Series Dalek variants