“My information comes from Lupin himself.”
He produced a piece of paper that was wet and crumpled. It was the page which Lupin had torn from his memorandum-book, and upon which he had written the phrase.
“And you will notice,” said Sholmes, with satisfaction, “that he was not obliged to give me that sheet of paper, and, in that way, disclose his identity. Simple childishness on his part, and yet it gave me exactly the information I desired.”
“What was it?” asked the baron. “I don’t understand.”
Sholmes took a pencil and made a fresh copy of the letters and figures.
“CDEHNOPRZEO—237.”
“Well?” said the baron; “it is the formula you showed me yourself.”
“No. If you had turned and returned that formula in every way, as I have done, you would have seen at first glance that this formula is not like the first one.”
“In what respect do they differ?”
“This one has two more letters—an E and an O.”