As Paul entered the private office he found the porter there, putting coal on the fire.
Stepping back to close the glass door behind him, that they might be alone, he said:
"Mike, who shuts up the office at night?"
"Sure I do, Mr. Paul," was the prompt reply.
"And you open it in the morning?" the young man asked.
"I do that!" Mike responded.
"Do you see that these windows are always fastened on the inside?" was the next query.
"Yes, Mr. Paul," the porter replied.
"Well," and the inquirer hesitated briefly before putting this question, "have you found any of these windows unfastened any morning lately when you came here?"
"And how did you know that?" Mike returned, in surprise.