Following Mrs. Sands, O'Reilly left the door between the two rooms open; but Beverley stepped quickly back and closed it.

"She's grand, the darling!" thought Clo. "Trust her to forget nothing. Her shutting that door proves how she counts on me."

The girl was deadly tired, and her head ached, yet she struggled up as the door clicked. O'Reilly had brought in her hat and dropped it on a table. There was no hat-pin, but Clo crushed the soft toque down over her masses of red hair, and hoped she was not untidy enough to be conspicuous. Unsteadily she tottered to another door—the door that led into the corridor. This faced a narrower passage to the kitchen and domestic offices of the flat. Clo would have to take that way because, if she ventured into the lift and showed herself in the hall below, the porter might take alarm. He might fear that Mrs. Sands' protÉgÉe was trying to escape for some sly purpose of her own, and refuse to let her go till he had telephoned upstairs.

In a quaint outside pocket of her new frock Clo had put the purse given her by Beverley. Through her adventures she had remembered to make sure occasionally that it had not dropped out. Now she opened the purse, selecting two ten-dollar bills and two of five dollars.

"That ought to do for 'em all," she said, "even if the lot are at home." And, money in hand, she ventured to the kitchen door. Only the chef and a woman assistant were at work.

"I'm Clo Riley, the girl Mrs. Sands has been good to," she eagerly explained. "I'm well again, and I have to go out. Mrs. Sands has a visitor, and I don't like to disturb them. Will you let me down your way?" So speaking she laid a ten-dollar bill and a five-dollar bill side by side on a table. She made no reference to the money, nor any gesture indicating it; nor did the others appear to see it.

The chef escorted her in silence to the servants' elevator. There was a button to push, and down the girl went, rejoiced at passing another stage of her journey. Five minutes more, and she was in a taxi, tearing back to the Dietz Hotel.

This time she marched boldly to a lift in a long row of half a dozen. "Fifteenth floor, please," she said, as if she owned the hotel; and was taken up without question. "Thanks to my swell clothes!" she thought. "Not far would I get in this place if I had on my old black!"

Armed with O'Reilly's key Clo threaded her way through several corridors and arrived at the door of his suite. Her fingers shook so that she could not find the lock, and as she fumbled for it, the door of an adjoining suite opened. The nerve-tried girl started as if she had been shot, and dropped the key on the carpet.

"Silly fool!" she scolded herself as she stooped to retrieve it, and to hide her face. If only the people (she knew by the voices they were man and woman) would pass before she had to look up! But they were in no hurry to pass. They had paused in front of their own door, and were talking in low tones—about her, Clo was sure!

In a big hotel, the chances were ten to one against their knowing O'Reilly. Raising her head, she tried to eye the pair with airy arrogance.

"I mustn't seem to care," she thought, and tried to wither them with a look before again attacking the keyhole. The woman was beautiful, a glorious, dark creature, gorgeously dressed and jewelled. But oddly it was the man who riveted Clo's attention, the man whose eyes gave the girl an electric shock. He was a tall, lanky, middle-aged individual, with auburn hair and a close-cut red beard streaked with gray. He walked with shoulders bent, and had no distinction, despite his well-cut evening clothes. But from under a pair of beetling black brows there flashed a light which took Clo's breath away. She didn't know what to make of his look. It was as if she'd been struck by lightning.

"My goodness, after all he must be a friend of O'Reilly's!" she feared. Even that supposition wasn't enough to account for the flash. Frightened, she slid the key into the lock, and almost falling into the room slammed the door behind her. She did not need to lock it, for without a key it could not be opened from the outside.

"I can hold the fort a few minutes now, whatever happens!"

In the corridor John Heron and his wife lingered in front of their own door.

"Well, if that's not the queerest thing I ever saw or heard of!" Heron exclaimed.

Coming out of their suite, they had caught an impressionist glimpse of a figure in white bent over the keyhole, then the figure had stooped for the dropped key, and mechanically they had paused in surprise.

"I wonder if she's made a mistake in the room?" Mrs. Heron had whispered, and Heron had returned:

"Yes, I think that must be so. She'll find it out and go somewhere else. O'Reilly isn't——"

There he had stopped short when the girl raised her head to face them; and when she presently vanished into his friend's room like a whirlwind, he neither finished his sentence nor answered his wife.

"What's the matter, Jack?" Mrs. Heron asked. "How odd you look!"

("Jack" was not a nickname that suited Heron, but his wife thought it debonair.)

"Why don't you speak?" she persisted.

"I was thinking," Heron said at last.

"Thinking what we ought to do?" his wife caught him up. "Shall we knock and ask O'Reilly if he's ready to go down with us?"

"No. We can't do that."

"I suppose not. But weren't you going to say it isn't like O'Reilly to have a girl calling on him in his rooms?"

"I don't remember what I was going to say," he snubbed her. "It doesn't matter, anyhow. After all, why shouldn't he? What is it to us?"

"Well, I feel queer about it," objected Dolores Heron. "The creature may be a hotel thief?"

"Nonsense!" fumed the man. "The girl was a child—sixteen or seventeen. We can't mix ourselves up in such an affair. Let's mind our own business."

"You needn't be so cross. I haven't done anything," Dolores reproached him. They went down together, and sat side by side on a rose-coloured brocade sofa in the immense salon generally known as the "hall." Not one of the ladies present was handsomer than Mrs. Heron, not one had more beautiful jewels or a more perfect dress, and all the men openly admired her—except her own husband.

Upstairs the girl in question was making the most of every moment. The queer little key attached to O'Reilly's watch couldn't belong to the desk, still, there might be a box inside the desk which it would fit. Clo searched everywhere and everything. At last, it seemed that nothing was left to try, when suddenly she recalled a paragraph in a newspaper. She had seen it in a Sunday Supplement. Why, yes, Miss Blackburne, the pearl-stringer, had given her the paper that Sunday long ago at Yonkers, to read on the journey home. The paragraph described the up-to-date feature added to some important hotel. Small safes had been placed in the walls of rooms for the benefit of guests, each key being different in design from every other. Clo could not remember the name of the hotel referred to. Perhaps it was this one. If not, the Dietz wasn't likely to let a rival get ahead of it. The girl stared at the wall. Any one of those panels might conceal a safe! There were lots of panels of different sizes, painted a soft gray and edged with delicate white mouldings. To test each would take hours (unless she had luck and hit on the right one first) for there might be a spring hidden in the flowery pattern of the moulding. But—it was to the left side of the room that O'Reilly had flung his anxious glance. She would begin, and hoped to end, her work on the left side. A few minutes spent in thinking out the situation, however, might save many minutes by and by. About those panels, for instance? Which were the most likely to hide a secret?

A frieze or skirting-board of gray painted wood ran round the room to a height of three feet above the pink-carpeted floor. Above this frieze, distributed at regular intervals, were large plaster panels, two on each side of the room, forming backgrounds for gold-framed, coloured prints; and between these were small, narrow panels, ornamented with conventional flower designs. Beneath and above the latter were panels still smaller, placed horizontally, and outlined with white curlicues and flutings. They were about four inches in height by ten inches in length; and on the left side of the wall there were two.

"Just the right size for nice big jewel boxes," Clo thought. "And the lower one's just the right height to open without stretching up. If I were putting a safe into a wall that's the place I'd choose!"

She passed her finger round the edge of one, the white-fluted edge, rather like the decoration of a fancy cake. Nothing happened. No spring clicked. She tried the other with the same result, then stood disappointed, only to return to the attack with new inspiration.

"I bet it pulls out!" she told herself. And—oh, joy, oh triumph!—it did pull out as she pressed her sharp little nails under the white fluting. The whole thing came away from the wall like the loose side of a box, having been kept in place by thin prongs of metal. Behind this cover was a steel or iron door of practically the same dimensions as the panel. It also was painted gray, and showed a tiny keyhole like a slit made with a pair of sharp scissors.

Clo deposited the cover close by on the desk, where it would be within reach if wanted in a hurry. Then she inserted the key attached to O'Reilly's watch. It slipped into place. It turned. It opened the small iron door, and Clo peered into the aperture. In the receptacle lay a pile of greenbacks held together with a paper band. There was also an envelope, but not the envelope the girl had pictured. It was larger, longer, wider, and thicker. It seemed to be made of coarse linen, and instead of the dainty gold seals with the monogram there were five official-looking red ones. Clo's heart contracted. It seemed too bad to be true. But there was plenty of space in this envelope to contain the other, as well as its contents.

"I'll have to open the thing and look," Clo half decided. But if she did, how could she make sure of what she wished to know? If the envelope with the gold seals had been removed, she had no means of recognizing the documents it had contained.

She took the linen envelope from the safe, and turned it over. Upon the other side was an address, written in a strong, peculiar hand: "Justin O'Reilly, care of The Manager, Columbian Bank, New York City," she read.

There was just one reason to believe that the envelope contained Mrs. Sands' papers; Clo's own strong, instinctive conviction.

Tentatively she pressed one of the seals. It cracked across. Another went the same way, and as she touched the third there came a sound of talking outside the door. "Open it for me with your pass-key, please," a man said. It was O'Reilly's voice.