"I should think it a part of your duty to find out," said The Thinking Machine, irritably.
The warden started to say some harsh things, then restrained himself and made a minute search of the cell and of the prisoner instead. He found absolutely nothing; not even a match or toothpick which might have been used for a pen. The same mystery surrounded the fluid with which the cipher had been written. Although the warden left Cell 13 visibly annoyed, he took the torn shirt in triumph.
"Well, writing notes on a shirt won't get him out, that's certain," he told himself with some complacency. He put the linen scraps into his desk to await developments. "If that man escapes from that cell I'll--hang it-I'll resign."
On the third day of his incarceration The Thinking Machine openly attempted to bribe his way out. The jailer had brought his dinner and was leaning against the barred door, waiting, when The Thinking Machine began the conversation.
"The drainage pipes of the prison lead to the river, don't they?" he asked.
"Yes," said the jailer.
"I suppose they are very small?"
"Too small to crawl through, if that's what you're thinking about," was the grinning response.
There was silence until The Thinking Machine finished his meal. Then:
"You know I'm not a criminal, don't you?"