"I don't believe I shall," said Eddy, absent-mindedly, as he picked up a card to which was pinned a beetle with a rainbow stripe down his back. "That's a beauty, isn't it?" "Yes, they're all fine. I think I'll hurry over and get a seat. You won't mind, will you? Look at them as long as you want." "Thank you!" said Eddy. "And be sure you latch the door, do you hear?" "All right," said Eddy, passing on to the next card. Payner hesitated as if not entirely satisfied with Eddy's answer; then turned to the door. "Just let down the catch, see?" he called once more, pausing with his hand on the fastening. "Yes, yes, I'll do it," returned Eddy, with a little petulance. It seemed hardly necessary that the injunction should be so often repeated. Payner went out, shutting the door behind him. Duncan Peck stood in the entry hallooing to some one below. He waited until the steps of the collector of coleoptera died away at the entrance of the building, then crept softly up to the door just closed, and gently tried it as he had done many times before. To his surprise it yielded to the pressure of his hand. Made cautious by a former experience, Duncan pushed the door very slowly until, through the widening crack, he perceived Eddy, standing before the table intent on the specimens. At this sight the evil-doer closed the door as softly as he had opened it, slipped back to his room, found his brother, and sent him over to the lecture to make sure of Payner's presence there. With great foresight, the Pecks had invented a device suited to just such an emergency as the present. They had prepared a little wooden plug which would almost fill the socket into which the door-latch springs, leaving but a thin edge to catch the latch. This slight hold of the latch would be sufficient to keep the door shut, but quite incapable of resisting pressure. As the locks of all the rooms were uniform, the plug which had been made to fit the Pecks' door could be counted on to produce the same effect on any door in the dormitory. Armed with this burglar's contrivance, Duncan crept back across the hall, pushed Payner's door ajar once more, and inserted his plug; then closed the door again and sneaked back to safety. In a few minutes the twins, secretly watching from their room, saw Eddy come out, slam the door, and go whistling downstairs. His whistle was still audible in the distance when Duncan stole down the entry and gave a hard push at Payner's knob. The door swung on its hinges. The long-desired opportunity had come at last!