"Penny is twelve minutes ahead of time.

He's not supposed to play during study-hour, you see, and unless I'm much mistaken he will be so informed before the night is much--" "_Hey, Penny! Cut it out, old top_!" From somewhere down the corridor the anguished wail floated, followed an instant later by sounds counterfeiting the howling of an unhappy dog.
Threats and pleas mingled.
"Penny! For the love of Mike!" "Set your watch back, Penny!" "Shut up, you idiot! Study's not over!" "Call an officer, please!" But Pennington Durkin was making too much noise on his instrument to hear the remonstrances at first, and it was not until some impatient neighbour sallied forth and pounded frantically at the portal of Number 13 that the wailing ceased.

Then, "What is it ?" asked Durkin mildly.
"It's only ten minutes to nine, Penny.

Your clock's fast again.

Shut up or we'll kill you!" "Oh!" said Penny surprisedly.