"By the way, what did you come down for?"

"I was hungry," said Jimmy. "I rather fancied a dry biscuit."

"There are some biscuits in a tin by your bed," said Rupert Bateman.

He was staring at Jimmy very intently through his horn-rimmed spectacles.

"Ah! That's where the staff work has gone wrong, old boy. There's a tin there with 'Biscuits for Starving Visitors' on it. But when the starving visitor opened it—nothing inside. So I just toddled down to the dining-room."

And with a sweet, ingenuous smile, Jimmy produced from his dressing-gown pocket a handful of biscuits.

There was a moment's pause.

"And now I think I'll toddle back to bed," said Jimmy. "Night-night, Pongo."

With an affectation of nonchalance, he mounted the staircase. Rupert Bateman followed him. At the doorway of his room, Jimmy paused as if to say good-night once more.

"It's an extraordinary thing about these biscuits," said Mr. Bateman. "Do you mind if I just—"