Finetime
Finetime was a human-descended colony on an inhabitable moon. The city's inhabitants were the 17 to 27 year old children of the rich inhabitants of the nearby Homeworld. The adolescents lived lives of party constantly connected to their Dots.
The city was surrounded by the Wild Woods, a lush jungle that the adolescents were warned was dangerous. Finetime itself was sealed off by a protective dome with strong enough security that the Doctor's TARDIS could not land there, as it was equipped with a DNA filter that only allowed authorised entities to enter.
When the Dots developed sentience and began to act against their users, they created man-traps, giant slug-like monsters, to kill and devour every Finetime resident (and as a side-effect, the citizens of the nearby Homeworld, which used the Dots as well, so that they could remain in contact with Finetime), in alphabetical order of their surnames. As a result, many of Finetime's residents were devoured by the monsters, with their Dots leading them to their deaths, due to the AI developing a dislike for racism, and having no safeguards in place to prevent it from attacking the residents.
After the Fifteenth Doctor and Ruby Sunday arrived on the moon, they helped several of the residents, including Lindy Pepper-Bean, find their way out of the city to escape the man-traps. The residents then rejected the Doctor's offer to relocate them because of his skin colour. (TV: Dot and Bubble [+]Loading...["Dot and Bubble (TV story)"])
