“Number Four is occupied by a bachelor alone, a Mr. Henry Orbit.” The inspector shook his head. “I don’t know how the keys of his house came to be in Parsons’ pocket, but that’s a detail. Here’s the private watchman now; come on.”

He moved out toward the gateway in the middle of the street but McCarty laid a detaining hand on his arm.

“Just one minute, Inspector. Well I know I’ve nothing to do with this case, if there is a case in it at all, but ’tis easier to change hats than houses, and if you stop by first at Number Four, and—and let me do the talking to whoever opens the door—?”

He hesitated and Inspector Druet flashed him a keen glance.

“What is it, Mac?” he demanded quickly. “Have you seen more than I have in this?”

“I’ve seen the corpse, sir,” McCarty returned evasively.

Along the enclosed street the solitary figure of the private watchman was advancing with quickened step. When he reached the gate the inspector spoke to him in a low but authoritative tone. The watchman uttered a startled exclamation and a brief colloquy ensued during which McCarty and Dennis gazed up the wide vista of the street beyond the high iron bars. In the glow of the lanterns which lighted the Mall the smooth pavement glistened like a sheet of glass under the dancing raindrops and the houses on either side, built of gleaming marble or the darker brownstone of an older period, looked like miniature palaces, with their vaguely outlined turrets and towers and overhanging balconies. Straight ahead loomed another gate, behind it the inky mass of foliage of the great park across the Avenue, untouched as yet by the season’s first frost.

“’Tis like a picture-book scene, even in the night!” Dennis remarked, and then he shook his head. “But it’s too restricted, entirely. For all its grandeur, the folks living in there will be having no more chance of keeping their private affairs one from the other than if ’twas a row of workman’s cottages out in the factory suburbs! ’Tis small mystery could last for long inside these gates!”

“I’d rather be outside them and free, than cooped up in there for all the millions these families have,” acquiesced McCarty. “The watchman’s opening up, though, and the inspector is beckoning. Will he be letting me have my way, I wonder?”

The great gates swung inward and the three passed in, the inspector leading and turning to the south sidewalk which was bordered by the houses bearing even numbers.