Alfred Smith climbed the creaky wooden stairs apprehensively, his eyes on the burly General Montcalm guarding the entrance at the top. To his relief, however, no invitation or ticket was demanded: his costume was sufficient validation. The red-faced general barely gave him a glance from under the plushly decorated cocked hat before waving him through.

It was crowded inside. Scores of Louis XIIIs, XIVs, XVs, and XVIs were dancing sedately with Annes of Austria and Marie Antoinettes to the strains of rhumba and cha-cha. Overhead, two colored chandeliers rotated slowly, unwinding the spectrum upon the glittering, waxed floor.

Where did he begin? He glanced at the platform where the musicians sat; they alone were not in costume. Lettering on the bass drum told the world that “Ole Olsen and His Latin Five” were providing the rhythms, but that did not seem like much to go on. No one here looked like an interstellar spy.

On the other hand, neither did Jones, Cohen, Kelly nor Jane Doe. They looked almost spectacularly ordinary. That was it: you had to find these people in the unlikeliest, most prosaic places.

Pleased by the inspiration, he went into the Men’s Room.

At first, he thought he had hit it exactly right. The place was crowded. Sixteen or so Musketeers stood around the washbasin, munching enormous cigars and conversing in low voices.

He insinuated himself among them and listened closely. Their talk was eclectic, ranging freely from the wholesale price of pastel-colored water closets to the problems of installing plumbing in a new housing development on Long Island that was surrounded by unsewered streets.

“I told the contractor to his face,” said a somewhat sallow, undersized Musketeer, knocking his cigar ash off against the pommel of his sword, “Joe, I told him, how can you expect me to lay pipe when you don’t even know the capacity, let alone the type—look, we won’t even talk about the type—of the sewer system they’re going to have installed out here?