It was twenty minutes past seven when that task was finished. Harry stood eyeing his grimy hands. “I guess I’d better wash my hands,” he decided. The water faucet was situated in a small room devoted to the book mail-orders, at one side of the department, and opened into it by two doors. There was no light and as Harry did not know the situation of the switch he felt his way to the faucet in the dark.

He had washed his hands, dried them on his handkerchief, and was about to pass out through the upper door when he heard subdued voices. Two men entered by the lower door and began to converse in low tones.

“You go and get it,” drawled a familiar voice. “Here’s the set, all wrapped. Keep to the lower end of the department. I’ll wait here until you bring my stuff. Make it flat, so I can button it inside my coat. You’d better take the books out one at a time. That’s a peach of a set. It’s full morocco. If Rexford ever misses it there’ll be some yelling.”

A dark, indistinct figure slipped from the lower door, another dimly outlined figure drew close to the side of a high desk out of sight of any chance intruder, while a third boyish figure sped across the department in search of Mr. Rexford, who had announced his intention of returning that evening to direct the preparation for the sale.

“Have you seen Mr. Rexford, Fred?” Harry’s eyes blazed with excitement, as he paused for an instant to question the other stock boy whom he met coming toward him, his arms full of books.

“Nope,” was the answer. “I don’t b’lieve he’ll show up. He hardly ever comes around when the fellows are workin’ at night.”

“But he said he’d be here.” Harry’s face was full of anxious concern.

“Well, mebbe he will, then. Don’t cry about it,” jeered Fred.

Harry did not answer this jibe. He merely smiled and set off in the direction of the buyer’s office. The door stood half open, but the office was dark, except for the faint light which shone into it from the department. “He isn’t there,” muttered the boy. “I’ll have to tell someone else.” He realized that if he did not act quickly the two men would have exchanged packages and gone. To prove their guilt it was necessary to surprise them in the mail-order room.

Harry darted from the buyer’s office and collided violently with a man who had stepped into his path from between two tables.