Surprise

The Doctor knew there was something wrong the instant he saw K9 wearing a top hat.

He was about to ask K9 if he had noticed anything odd when the door handle began to turn. The Doctor spun around, bulging eyes fixed on the slowly opening door.

And a Cyberman entered the room.

"Ah," said the Doctor, then tried to think of some random nonsense to throw the monster off guard.

"Awfully good, isn't it?" said the Cyberman.

And it pulled of its head.

"Romana...what are you doing?"

"It's K9's birthday, Doctor. I thought we'd have a fancy dress party!"