As Ace is out looking for her friends, the Doctor has taken to cat hunting. A strange black cat seems to be following him around. Visiting a local shop for cans of cat food, the Doctor tries in vain to capture the animal. As he continues to do this he's running through peoples lawns and yards which draws the attention of the local neighbourhood watch. The Doctor manages to lose Sergeant Paterson, the persistent SAS survivalist, and is about to catch the black cat when he hears Ace shouting for help.
This was the final episode of the classic Doctor Who series. The final shot is the Doctor and Ace walking off towards their next adventure.
"There are worlds out there where the sky is burning, and the sea's asleep, and the rivers dream. People made of smoke, and cities made of song. Somewhere there's danger, somewhere there's injustice, and somewhere else the tea's getting cold! Come on Ace, we've got work to do!" - The Doctor