He and Stanley went across the campus and down Maple Street about eight. Spooner’s was a large, square house standing almost flush with the sidewalk. Like many of the residences thereabouts, its upper floors were tenanted by students unable or disinclined to secure rooms on the campus. Stanley pulled open a squeaky screen door and entered. At the foot of the staircase, he paused and lifted his voice. “Oh, Rusty!” he shouted. “Rusty-y-y!” Somewhere above a door opened and a voice answered. “A-a-ay! Come up!” Stanley led the way again up two flights, and then to a door at the front of the house. Oddly enough, it was closed tightly, which fact, since it had been opened a moment before, struck Dick as peculiar. Stanley knocked and a voice called “Come in!” Somehow Stanley managed to get behind Dick, and it was Dick who turned the knob and pressed the door inward. The next instant he was precipitated into a glare of light. The knob had jerked itself out of his hand, and something--he supposed at the moment the something to have been Stanley--had banged against his heels and pushed him violently into the room. He stopped to find himself asprawl over an armchair with a placard bearing the word WELCOME a few inches from his nose. “Good evening,” said Rusty amiably from across the room. [Illustration: _“Good evening,” said Rusty amiably_] “Hello,” gasped Dick. Then he looked back at the door for Stanley. Stanley was not there. But at the instant the door opened again and Stanley appeared. He was grinning broadly, but Dick was too much interested in the door to see it. The door was not opening like any door Dick had ever seen. In the first place it was turning on pivots at top and bottom, half of it coming in, and half of it going out, so that the aperture for entrance was scarcely wider than Stanley. In the second place, Stanley was holding hard to that knob and being fairly dragged through, for above the sill and below the lintel was a coiled spring that, so soon as the knob was turned, swung the door swiftly on its axis from left to right. Dick stared in surprise. “Just a little idea of my own, Bates,” said Rusty, coming forward and removing the placard from the back of the chair to a place on the wall. “Have a chair.” Dick looked from the proffered chair to Rusty and then to Stanley and shook his head. “No, thanks,” he muttered. “I’ll stand!” However, Stanley assured him on oath that the chair was quite safe and wouldn’t double up under him and he consented to try it, although not without anxiety. But he was up again a moment later, demanding to be shown the working of the amazing door.