But late as they were they were not the only occupants of the lift.  Returning from a masquerade, a domino over his arm, stood Falconer.  Civilly enough he returned Billy’s greeting, with no apparent awareness of the little lady in pongee, but Billy was conscious that her flaunting caliber had been promptly registered.  And to his annoyance the actress raised big eyes of reproach to him.

“No champagne for me, after all, Mr. Billy!” she sighed.  “You are not very good for a celebration—­h’m?...  Well, then—­good night.”

Her parting smile as she left the car adroitly included the tall aristocratic young Englishman with the little moustache.

Sharply Billy turned to him.  “Come up to my room, please.  I have something to say to you.”

In silence Falconer followed.  Billy flung shut the door, drew a long breath, and turned to him.

“Do you know where I got that girl?” he demanded.

It took several seconds of Falconer’s level-lidded look of distaste to bring home the realization.

“Oh, see here,” he protested, “wait till you understand this thing....  I pulled that girl over Kerissen’s back wall at ten o’clock to-night.  I thought she was Miss Beecher, but a mistake had been made and the wrong girl arrived.  But the point is this—­Arlee Beecher is in that palace.  This girl saw her and talked with her last night.  Now we’ve got to get her out.  It’s a two-man job,” said Billy, “or you’d better believe I’d never have come to you again.”

He had given it like a punch, and it knocked the breath out of Falconer for one floored instant.  But he was no open-mouthed believer.  The thing was more unthinkable to him than to Billy’s romantic and adventurous mind, and the very notion was so revolting that he fought it stoutly.

From beginning to end Billy hammered over the story as he knew it, explaining, arguing, debating, and then he drew out the plans of the palace and flung them on the table by Falconer while he continued his excited tramping up and down the room.

Falconer studied the plans, worried his moustache, stared at Billy’s tense and resolute face, and took up the plans again, his own chin stubborn.

“Granted there’s a girl—­you can’t be sure it’s Miss Beecher,” he maintained doggedly.  “This Baroff girl had no idea of her name.  Now Miss Beecher would have told her name, the very first thing, it appears to me, and the names of her friends in Cairo, asking for the Baroff’s offices in getting a letter to me—­us.”

“She may have been too hurried to get to it.  She had so many questions to ask.  And she probably expected to see the girl again the next day or night.”

“Possibly,” said Falconer without conviction.

“But where, then, is Miss Beecher?”

“We may hear from her to-morrow morning.”

“We won’t,” said Billy.

Falconer was silent.

“Good Lord!” the American burst out, “there can’t be two girls in Cairo with blue eyes and fair hair whom Kerissen could have lured there last Wednesday!  There can’t be two girls with chaperons departing up the Nile!  Why—­why—­the whole thing’s as clear to me—­as—­as a house afire!”