Gatecrashers (short story)

 was the first short story in The Target Storybook.

Publisher's summary
to be added

Plot
The Doctor lands the TARDIS inside an enclosed Pizza-Porter parlour, where a Gornt worker, Iz, lies dead. Deciding to investigate the ‘locked room’ murder, the Doctor uses the location codes on Iz’s teleporter to send Yaz and Ryan to the girl’s home, while she and Graham take the TARDIS to the mall of New Port City. Outside the mall, the Doctor and Graham find a city smashed by the teleport signals that send the populace whizzing from one sealed-off section to another, the hastily-repaired houses protected by makeshift force-fields. Finding Iz’s enclosed room full of imaginative drawings, Yaz and Ryan use a one-off code on the teleporter to view the site of a party Iz had visited. Returning to the pizza parlour, the Doctor and Graham find a note from their friends, but are unable to follow with the teleport code. Using the TARDIS to track the party to the local power plant, the Doctor and Graham set off on a handy scooter, avoiding the teleport superhighways in their path as they go. Yaz and Ryan are captured by the city’s Mayor, Ronan Sumners, who has been luring people to his parties to steal their brains’ imagination-boosting sperantium, using it to power his city and keep the Gornt ‘safe’ inside their enclosed rooms. After explaining how Iz was mortally wounded trying to escape, the Mayor attempts to drains Yaz and Ryan’s brains; luckily for them the Doctor and Graham burst in, interrupting the official’s plan. When the Mayor tries to escape the Doctor sonics his teleporter’s codes, inadvertently transporting the Mayor inside the Pizza-Porter’s oven. The Doctor destroys the power plant and helps free the Gornt populace from their prisons, enabling them to go anywhere their imaginations will send them

Characters

 * Thirteenth Doctor
 * Graham O'Brien
 * Ryan Sinclair
 * Yasmin Khan
 * Iz
 * Ronan Sumners

Worldbuilding

 * The pizza parlour uses spray cheese and Pizza-Porter ovens for "deep-pan transportation".
 * Yaz refers to having dealt with cases of domestic violence back home.
 * The Doctor exclaims that she's "not Derren Brown!"
 * The current Mayor of New Port City is Ronan Sumners.
 * Ryan offers to play tiddlywinks with Yaz using frozen pepperoni.

Continuity

 * Team TARDIS have only just left 17th century Lancashire. (TV: The Witchfinders)