"Look, I don't care how many times you swear that it's true, there are no aliens in Cardiff!" PC Andy told the man he had just arrested. "I think you've had too many to drink. A night in the cells to sober up is just what you need."
"But it was bloody huge! I tell you, it wasn't like anything I've ever seen before," the man cried as Andy shut the door on the cell. "Don't lock me up! I'm not going mad, honestly. I've only had a couple."
"How far outside Cardiff have you ever been?" Andy shouted through the door.
"I went to Scotland once."
"Well, there you go then. That creature that you saw, it's from Cornwall. You don't see them much around these parts much but occasionally one finds its way across the border."
The man on the other side of the door fell silent as he considered the idea.
"I suppose that explains it," he replied eventually.
"Right, I'll come back later. Might even bring you a cup of tea, if you want," Andy offered.
As soon as he was out of ear shot of the cells, Andy called Gwen Cooper. That cup of tea needed a special ingredient only Torchwood could provide. A tiny memory loss pill called Retcon.