Kirsty Fisher was a girl who lived with her family. Her mother suffered from Munchausen by proxy, and often took Kirsty to see the doctor. Kirsty believed her mother put things in her food to make her sick.
One day Kirsty learned from her brother, David, that there was a flying-saucer-watching meeting the next day. Kirsty sneaked out of the house to attend, and on the way met Ace, who accompanied her to the meeting. However, when Ace started to make fun of Chester, the man running the meeting, Kirsty became upset and ran away.
She ended up at the newsagent shop, and Mr Golieweski gave her some chocolate. Kirsty started to feel dizzy. When Ace arrived at the shop, Mr Golieweski turned to greet her, and Kirsty saw that the back of his head had been opened up and it was now a flap of skin covering something. Kirsty saw Mr Golieweski throw Ace across the room, then she blacked out. When she woke, both she and Ace were locked in a cupboard. While Ace worked at picking the lock, Kirsty told her about her life. The lock opened and they escaped, to find that the alien that had taken Mr Golieweski's form was fighting the Seventh Doctor. The three of them escaped when the Doctor noticed that the alien's people had come to punish him.
After the newsagent shop had exploded, taking the alien with it, Kirsty ran home. Ace was disappointed, thinking that Kirsty could have joined them in the TARDIS.
Kirsty returned home and told her mother the entire story. Her mother, thinking Kirsty delusional, was pleased to note that Kirsty would need to see some experts and take some special tests. (PROSE: Monsters)