K1

The Experimental Prototype Robot K1 was a robot designed and built by Professor J.P. Kettlewell of Think Tank. It was intended to eventually replace humans in difficult and dangerous tasks, including mining operations, activities involving radioactive material, and thousands of other tasks.

It was created when Kettlewell discovered a metal, which he called "living metal", that could grow with the robot. Though the robot was very big, it was very good at manipulating devices and could even operate the disintegrator gun that it was given by Think Tank.

It had a very literal mind and was fitted with a Prime Directive, based off of Kettlewell's own mind, intended to keep it from killing humans. Should it kill humans, it would become confused and go mad.

The people of Think Tank, who were part of the Scientific Reform Society, used the robot to steal the components of the disintegrator gun and destructor codes for the missiles of America, China, and Russia. When Sarah Jane Smith met it, she cared for it, being confused by the orders it had to kill.

When it killed Kettlewell, it developed an Oedipus complex and took Sarah captive, planning to keep her safe as it launched the missiles. It would destroy mankind and build more machines like itself, claiming that machines do not lie.

The countries activated their fail safe codes and stopped the launch. As the robot attempted to escape, the Brigadier shot it with the disentegrator gun, but the effect made it grow to enormous size. It took Sarah and placed her on top of a building, away from harm as it attacked UNIT.

The Fourth Doctor, having created a metal virus that Kettlewell also discovered, took a bucket of the liquid and, riding in Bessie, splashed the robot with the virus. It ate away at the robot until it returned to its normal size and disintegrated. (DW: Robot)

Professor Kettlewell's work was suppressed during the subsequent cover-up, but the technology was used to develop new projects. Later, in the 26th century, one of the ancient robot prototypes - labelled 'K3' - was found and stolen by Robert Eliot Whitman, with the intention of helping build a colony on the remote planet Jegg-Sau; the colonists activated it and used it to build a workforce of similar robots. However, the colonists were forced to abandon the planet and leave the robots behind, leaving them confused and lonely. Hoping to restore his ancestor’s reputation and claim some of the patent royalties, Kettlewell's descendant Ethan Kalwell traced Whitman's robot to the abandoned colony, only to find four of the robots there. A year after Kalwell's shuttle crashed, Bernice Summerfield also crashed while flying over Jegg-Sau. The robots, driven mad by their isolation, absorbed energy and used it to grow to giant size to attack the jets coming to rescue Benny. She tried vainly to contact the jets and get them to call off their attack, but her pleas were lost and the robots were eventually destroyed. (BFBS: The Relics of Jegg-Sau)

Behind the scenes

 * Matt Smith claims he would like the Eleventh Doctor to face K1 again, perhaps forshadowing a return.
 * K1 is a homophone of Finnish word, kone which means machine, rather fittingly.
 * When the K1 robot was being restored for The Doctor Who Experience, it was found in such a poor condition it was almost entirely rebuilt.