ng was it?" asked Paul, pushing his advantage.

"It was last Monday mornin', Mr. Paul," the porter explained, "an' how
it was I dunno, for I had every wan of them windows tight on Saturday
night, an' Monday mornin' one of them was unfastened whin I wint to
open it to let a bit of air into the office here."

"You sleep here always, don't you?" Paul proceeded.

"I've slept here ivery night for three years now come Thanksgivin',"
Mike replied. "I've the whole top of the house to myself. It's an
illigant apartment I have there, Mr. Paul."

"Who was here Sunday?" was the next question.

"Sure nobody was here at all," responded the porter, "barrin' they came
while I took me a bit of a walk after dinner. An' they couldn't have
got in anyway, for I lock up always, and I wasn't gone for an hour, or
maybe an hour an' a half."

"I hope you will be very careful hereafter," said Paul.

"I will that," promised Mike, "an' I am careful now always."

The porter took up the coal-scuttle, and then he turned to Paul.

"How was it ye knew that the winder was not fastened that mornin'?" he
asked.

"How did I know?" repeated the young man. "Oh, a little bird told me."

When Mike had left the office Paul took a chair before the fire and
lighted a cigar. For half an hour he sat silently thinking.

He came to the conclusion that Mr. Wheatcroft was right in his
suspicion. Whittier, Wheatcroft & Co. had lost important contracts
because of underbidding, due to knowledge surreptitiously obtained. He
believed that some one had got into the store on Sunday while Mike was
taking a walk, and that this somebody had somehow opened the safe.
There never was any money in that private safe; it was intended to
contain only important papers. It did contain the letter-book of the
firm's bids, and this is what was wanted by the man who had got into
the office, and who had let himself in by the window, leaving it
unfastened behind him. How this man had got in, and why he did not get
out by the way he entered, how he came to be able to open the private
safe, the combination of which was known only to the two
partners--these were questions for which Paul Whittier had no answer.

What grieved him when he had come to the conclusion was that the
thief--for such the house-breaker was in reality--was probably one of
the men in the employ of the firm. It seemed to him almost certain that
the man who had broken in knew all the ins and outs of the office. And