"Hot water, please," said Lupin.

The other looked at him with an air of mingled amazement and rage.

"Oh," said Lupin, "and a bath-towel! By Jove, there's no bath-towel!"

The man growled:

"You're getting at me, aren't you? You'd better be careful!"

He was going away, when Lupin caught him roughly by the arm:

"Here! A hundred francs if you'll post a letter for me."

He took out a hundred-franc note, which he had concealed during the search, and offered it to him.

"Where's the letter?" said the warder, taking the money.

"Just give me a moment to write it."