The detective, walking a little in advance of his companion, stepped forward to a hall-table and knocked loudly on its polished surface. No answer came. He went further along, to the head of a railed stair which evidently communicated with a cellar kitchen; again he knocked, more loudly than before, on an adjacent panel, and again got no reply. And at that, turning back along the hall, he opened the door of the room which faced upon the street, and he and Hetherwick looked in. A musty-smelling, close-curtained room that, a sort of Sunday parlour, little used, cold and comfortless in its formality. But the room behind it, to which Robmore turned next, showed signs of recent occupancy and life. There was a fire in the grate, with an easy chair drawn near to it; on the table close by lay women's gear—a heap of linen, with needle and thread thrust in, a work-basket, scissors, thimble; it required no more than a glance to see that the owner of these innocent matters had laid them down suddenly, suddenly interrupted in her task.  
"I'll tell you what it is, Mr. Hetherwick!" exclaimed Robmore abruptly. "This house is empty! Empty of people, anyway."
 
"Silent enough, to be sure," agreed Hetherwick. "The woman——"
 
"You've frightened her by calling here," said Robmore. "Then she slipped round to Pencove Street. And there she found Ambrose dead! She's some connection with him and Baseverie, because she possesses a key that admits to that yard. And finding Ambrose dead, she came back here, got her things and cleared out. There isn't a soul in this house. I'll lay anything on that!"
 
"It struck me that this might be the place where the two ladies were detained," remarked Hetherwick.
 
"We'll soon see about that," declared Robmore. "Come upstairs—we'll search the place from top to bottom. But stop, downstairs first."
 
He ran down the stair to the cellar kitchen, with Hetherwick at his heels. And at the door he laughed, pointing within.
 
"Look there!" he exclaimed. "I told you you'd interrupted things. See! there's one tea-tray, laid out all ready for two—cups and saucers, teapot, bread and butter cut, cake. There's another for one. And there's the kettle, singing away like a bird on a bough. What's that mean? The woman was going to carry up tea for two, somewhere; t'other tray was for herself. Well, you nipped that in the bud; she'll have to get her tea somewhere. But—the others? Come upstairs."
 
Going back to the hall, he led the way up the main staircase. There were two stories above the ground floor; on the first were rooms the doors of which, being opened, or being found open, revealed nothing but ordinary things: of these rooms there were three, opening off a main landing. But on the next floor there were only two rooms; one was unfurnished: at the door of the other, a few inches ajar, the detective immediately paused.
 
"Look you there, now, Mr. Hetherwick!" he said, pointing here and there. "Here's recent work! Do you see that a strong bolt, more like a bar, has been fitted on the outside of this door, and the door itself fitted with a new patent lock, key outside? And, good Lord! a chain as well. Might be in a gaol! But what's inside?"
 
He pushed the door open and revealed a large room, fitted with two small beds, easy chairs, a table on which books, magazines, newspapers lay; on the table, too, was fancy-work which, it was evident, had been as hastily laid aside as the sewing downstairs. Hetherwick bent over the things, but Robmore went to the one window.
 
"Gaol, did I say?" he exclaimed. "Why, this is a gaol! Look here, Mr. Hetherwick!—window morticed inside and fitted with iron bars outside. Even if whoever's been in here could have opened the window, and if there'd been no bars there, they couldn't have done anything though, for there's nothing but a high blank wall opposite—back of some factory or other, apparently. But what's this?" he added, opening a door that stood in a corner. "Um! small bathroom. And this," he continued, going to a square hatch set in the wall next to the staircase. "Ah! trap big enough to hand things like small trays through, but not big enough for a grown person to squeeze through. Well, I shouldn't wonder if you're right, Mr. Hetherwick—this, probably, is where these ladies were locked up. But—they're gone!"
 
Hetherwick was looking round. Suddenly his eyes lighted on a familiar object. He stepped forward, and from a chair near one of the beds, picked up a handbag of green silk. He knew it well enough.
 
"That settles it!" he exclaimed. "They have been here! This is Miss Han—I mean Miss Featherstone's bag—I've seen her carry it often. These are her things in it—purse, card-case, so on. She's left it behind her."
 
"Aye, just so!" agreed Robmore. "As I say, they all left in a hurry. I figure it out like this: the woman, who, of course, acted as sort of gaoler to these two unfortunate ladies, when she made that discovery round yonder, came back here, got her outdoor things, and cleared off. But before she went, she'd the decency to slip up here, undo that chain, slip the bolt back, and turn the key! Then, no doubt, she made tracks at express speed, leaving the ladies to do what they liked. And they, Mr. Hetherwick, having a bit o' common sense about 'em, did what I should ha' done—they hooked it as quick as possible. That's that, sir!"
 
Hetherwick thrust Rhona's handbag into his pocket and made for the door.
 
"Then I'm off, Robmore," he said. "I must try to find out where they've gone. I've an idea probably they'd go to Penteney's office. I'll go there. But—you?"
 
"Oh, I'm going back to Pencove Street," answered Robmore. "Plenty to do there. But off you go after the ladies, Mr. Hetherwick, there's nothing you can do round here now. I'll keep that clerk of yours a bit, and the Jew chap—they might come in. We shall have some nice revelations in the papers to-morrow, I'm thinking, especially if Matherfield has the luck he expects."
 
"What are you going to do about this house?" asked Hetherwick as they went downstairs. "Do you think the woman will come back?"
 
"Bet your life she won't!" answered Robmore. "Not she! I should think she's half-way across London—north, south, east or west, by this. House? Why, I shall just lock the front door and put the key in my pocket. We shall want to search this house narrowly."
 
Hetherwick bade him good-day for the time being, and hurried off to Victoria Street, to fling himself into the first disengaged taxi-cab he encountered, and to bid its driver go as speedily as possible to Lincoln's Inn Fields. He was anxious about Rhona—and yet he felt that she was safe. And he was inquisitive, too; he wanted to hear her story, to find out what had happened behind the scenes. He felt sure of finding her at Penteney's office; she and Madame Listorelle, once released from their prison, would naturally go there.
 
But the clerk whom he encountered as soon as he rushed into the outer office, damped his spirits at once by shaking his head.
 
"Mr. Penteney's not in, sir," he answered. "He was in until not so long ago, but he got a telephone call and went out immediately afterwards. No, I don't know who it was that rang him up, Mr. Hetherwick, nor where he went; seemed a bit excited when he went out, and was in a fearful hurry."
 
Hetherwick concluded that Madame Listorelle had summoned Penteney, and that he had gone to meet her and Rhona. He went away, somewhat at a loss—then, remembering that Matherfield had promised to wire from Southampton, he turned towards his chambers. At the foot of the stairs he met his caretaker.
 
"Been a young lady here inquiring for you, Mr. Hetherwick," said the man. "Been here twice. I said I didn't know when you'd be in—any time or no time. She said—but there is the young lady, sir—coming back!"
 
Hetherwick turned sharply and saw Rhona coming across the square. Hurrying to meet her and disregarding whatever eyes might be watching them, he took both her hands in his in a fashion that brought the colour to her cheeks.
 
"You're all right—safe?" he asked quickly.
 
"Sure?"
 
"I'm all right and quite safe, thank you," she answered. "I—I've been here twice before, but you were out. I came to borrow some money. I left my bag and purse in—the place where we were locked up, and——"
 
Hetherwick pulled out the handbag and silently gave it to her. She stared at him.
 
"You've been—there!" she exclaimed. "How——"
 
"Got in this afternoon, an hour ago," he answered. "Here, come up to my rooms! We can't stand talking here. Madame Listorelle—where's she?"
 
"I left her at Victoria, telephoning to Major Penteney," replied Rhona. "She, too, had no money. She wanted me to wait until Major Penteney arrived, but I wouldn't. I walked here. I—I thought you'd want to know that we'd got out—at last."
 
Hetherwick said nothing until they had entered his sitting-room. Then, staring silently at her, he put his hands on Rhona's shoulders, and after a long look at her, suddenly and impulsively bent and kissed her.
 
"By gad!" he said in a low voice. "I didn't know how anxious I was about you until I saw you just now! But—now I know!"
 
Then, just as suddenly, he turned away from her, and in a matter-of-fact manner lighted his stove, put on a kettle of water, and began preparations which indicated his intention of making tea. Rhona, from an easy chair into which he had unceremoniously thrust her, watched him.
 
"Liberty!" she said suddenly. "We're both discove............