Escorted by Wilson, who seemed to take a particular interest in this work, he studied each room and found similar chalk-marks in two of the others. He also observed two circles on some oak panels, an arrow on a wainscoting and four figures on four steps of the staircase.
After an hour spent in this way, Wilson asked:
"The figures are correct, are they not?"
"I don't know if they're correct," replied Shears, whose good temper had been restored by these discoveries, "but, at any rate, they mean something."
"Something very obvious," said Wilson. "They represent the number of planks in the floor."
"Oh!"
"Yes. As for the two circles, they indicate that the panels sound hollow, as you can see by trying, and the arrow points to show the direction of the dinner-lift."
Holmlock Shears looked at him in admiration:
"Why, my dear chap, how do you know all this? Your perspicacity almost makes me ashamed of myself."
"Oh, it's very simple," said Wilson, bursting with delight. "I made those marks myself last night, in consequence of your instructions ... or rather Lupin's instructions, as the letter I received from you came from him."