After the eruption of mount Krakatoa in 1883, one of the Xyloks was found in the post-volcanic aftermath. It was eventually passed to Sarah Jane Smith by a geologist friend when she was researching volcanic activity, 18 months prior to the events of The Lost Boy. During her studies of the crystalline structure, she found that it could use her laptop to communicate. The Xylok agreed to help Sarah Jane protect Earth, and was integrated into the supercomputer Mr Smith, built by Sarah Jane under the instruction of the Xylok. Unbeknownst to Sarah Jane, this was a plot, in anticipation that it would one day be able to release the imprisoned Xylok race. Sarah Jane and her companions were able to thwart its intentions; as a result, Mr Smith was reprogrammed and became a benefit to the human race once again.