"Mildred" was the name given by Jack Harkness to a "zombie" which he and Ianto Jones caught in Trowbridge. Ianto suggested the name Kylie, to which Jack replied: "In those shoes? No way!".
At the Torchwood Hub, Mildred was confined to the holding cells, where she was placed in the cell next to Janet.
Jack and Ianto later returned to Mildred and hauled her to the main area of the Hub, where they strapped her into the interrogation chair. Sensor pads were attached to her head to monitor her brain activity and they took samples of her blood, skin and hair. Mildred was then subjected to a full body scan, which was actioned using the Bekaran deep-tissue scanner.
After a zombified Trystan Thomas attempted to attack the pair, Jack and Ianto decided to move Mildred and transfer Trys to the interrogation chair. They sealed Mildred's mouth with a strip of duct tape and, using a choke-loop, moved her to one of the Hub's support stanchions. As they attempted to move her, however, a musical warbling filled the hub, starting as a song, then growing louder into the shriek of an alarm. Jack and Ianto discovered that it was emanating from a pod on a nearby workbench which was reacting to Mildred's proximity.
Mildred was a small girl, but was as lively as a Weevil. She wore a blood-spattered Girls Aloud t-shirt. (PROSE: Bay of the Dead)