Mr. Smith
Mr Smith
Vital statistics
Name Mr. Smith
Title Mr Smith
Alias The Xylok, Super Computer
Status Alive
Friend/Foe Neutral
Home Planet the Xylok meteorite
Species Xylok

Mr. Smith is a super computer in Sarah Jane's attic. He ultimately helps them save the Earth many times, but mostly scans and gives information on aliens and alien objects.


Mr. Smith is a giant super computer hidden behind a chimney breast in Sarah Jane's attic. Sarah Jane was given a crystal from the great eruption of Krakatoa by a scientist for analysis. After leaving the crystal by her desktop one night, she found it started to comunicate with the desktop and it then it spoke to Sarah.

Eventually (after being assisted by Sarah Jane) it grew into the Mr. Smith we know and love today. After helping Sarah Jane, Clyde, Luke and Maria we find out in the episode The Lost Boy that Mr. Smith is in fact a Xylok, a crystalline life form who's purpose is to destroy the Earth and release the rest of his race from beneath the Earth's crust, where they had been buried for sixty million years after crashing to Earth as a meteorite.

Eventually, after Maria's dad (Alan Jackson) uploaded an apocalypse virus to Mr. Smith, Sarah Jane did reprogram him to have a new purpose- defending the earth. After this, Mr. Smith defended the earth with Sarah Jane many times.


Mr. Smith is very deadpan, and has no sense of humour until he is rebooted. After the reboot, Sarah Jane remarks that he has gained a sense of humour. When she makes this remark, he runs his diagnostics. He originally does not like K9, but eventually begins to warm to 'that metal dog' and says he will miss him when he goes with Luke to Oxford.

Other InformationEdit

Mr. Smith has a defense gun and a self-destruct system. He also has the ability to do things like track Sarah Jane's car.

Behind the ScenesEdit

  • Mr. Smith's voice made an appearance on Doctor Who in Stolen Earth and Journey's End


  • Mr. Smith's only on-screen battle was with K-9.

External LinksEdit

To be added.