Dorothy turned over the piece of paper to find as she expected that the other side was blank. No signature. Nothing but the double warning, and the admonition to destroy the missive and to do so at once. Evidently the writer either believed or knew for certain that she would shortly be disturbed. There was no fireplace in the bedroom. Even though she tore the note into bits, some of the scraps might be found and pieced together should she throw them out the window; and her room might be searched at any time. How could she make way with it? For a moment or two Dorothy was at a loss. Mechanically her fingers tore the paper into fine shreds.

Then she smiled. “I guess we’ll let the plumbing take care of you,” she said, gazing down on the little pile of paper on her palm, and she disappeared into the bathroom.

When she returned, Dorothy opened Janet’s over-night bag, took out a pair of green silk pajamas, bedroom slippers and toilet accessories, among which was a new toothbrush in a case. This, and the underwear she had on were the only belongings of her own that she had retained.

From Janet’s purse, she extracted the trunk key. After some rummaging in that large travelling wardrobe, she found a quilted bathrobe of pale pink satin on a hanger toward the back. It was too late to unpack entirely, and she was about to close and relock the trunk, when she decided to leave it open. The Janet Jordan she was portraying had never waked up at the famous meeting of last week. That Janet would feel outraged at her imprisonment, her father’s seeming callousness and would naturally be furious at being packed up here willy-nilly: but she would have no cause to be suspicious of these people in this big stone house. If she had locked the trunk – Dorothy realized she had almost made a mistake, although a minor one – and in her present position mistakes were dangerous affairs.

Although it was very late and the day had been a strenuous one Dorothy did not feel tired. While she undressed, she went over in her mind the new vistas opened up by this mysterious note she had just destroyed. As she dissected it word by word from memory, she was astonished to find that the scrap of paper carried much interesting information between the lines.

Undoubtedly, Ashton Sanborn had planted a member of his organization in the house, but how that had been possible, she could not imagine. First of all, there was the warning to be on her guard. That Mrs. Lawson was indicated she had no doubt. Her hostess, while seeming most charming and courteous, had nevertheless suggested the hot lemonade which the note told her not to drink. It was quite likely that her unknown adviser had reason to think that the lemonade would be drugged. And then these people could hardly mean to poison her so soon after her arrival. For their whole idea in bringing her to Winncote, as she understood it, was to make sure whether the real Janet had heard their secrets or not. No – they merely wanted her to sleep soundly. But why?

Dorothy pondered on this for several minutes. There could be only one reason, she decided. Somebody was planning to enter her bedroom tonight, and wished to do so without her knowledge. What their purpose might be she could not guess and she did not bother about it. To a girl of a nervous temperament, such as Janet Jordan, the knowledge that such a visit was planned and success arranged for by means of a drug, would have been torture. But Dorothy, who could feel “Flash” in his holster just above her knee was merely worried for fear that lemonade or no lemonade she would fall asleep. The arrival here had been uneventful enough after what had happened at the Jordans’ apartment. At least, to all outward appearances it had been smooth sailing. She was beginning to realize that nothing with these people was what it seemed to be. She had climbed her Vesuvius and was standing at the crater’s edge. Already the first rumblings of the eruption had been heard.

Her position, though seemingly secure, was nothing of the kind. The sooner Ashton Sanborn gave her the orders he had promised, and she could carry them out and get away from this place, the better for Dorothy Dixon. And yet she could not help a feeling of exhilaration.

There came a gentle knock on her door. Wearing her quilted wrapper and slippers she turned the key and opened to – the imposing Tunbridge. He bore a small tray on which stood a steaming tumbler, a bowl of sugar, two spoons and a napkin. “Your hot lemonade, Miss Jordan,” he announced in his pompous voice and rather as though he were offering her a priceless gift. “Mrs. Lawson’s instructions are to drink it after you get in bed, Miss. May I mention also that it is very hot?”

Dorothy took the tray. “Thank you, Tunbridge, I’ll be careful. Good night!”

“Good night, Miss.”

The butler departed in the direction of the stairway, and Dorothy closed the door and locked it again.

She set the tray on a chair beside her bed and put two spoonfuls of sugar into the tall glass. It was too hot for anyone to drink yet, so she went into the bathroom to get ready for bed.

Five minutes later she switched off all the lights except the one on the head board. Then she got into bed, picked up the glass and stirred her lemonade, making sure that the spoon tinkled against the glass. If anyone was listening outside her door they would naturally think she was drinking the stuff.

After waiting a moment or two longer, she set the glass down on the tray with a thump that might have been heard on the gallery. But the glass remained in her hand. Off went her light now, and still holding the lemonade she got quickly and quietly out of bed. A silent trip to the bathroom in the dark and she emptied the lemonade into her washbowl. Then she came back and placed the empty glass on the tray. She hurried over to the bow window, opened a sash, turned off the heat in the radiator and crawled into bed again.

The bed was to the left of the door as one entered the room. By lying on her right side Dorothy held the entire room within her view. After the soft glare from the shaded electric lights, it seemed inky black, but soon her eyes grew accustomed to the gloom. In the wall just beyond the foot of the bed was the closed door of her closet. The trunk stood beyond that in the corner. The alcove and window seat took up a large section of the farther wall and in the corner, diagonally across from where she lay was a dark spot – the writing desk. Opposite her bed was the half open door to the bathroom. The dressing table, the door to the hall but a few feet from her head – mentally she had completed her tour of the room.

Then for a long while, or so it seemed to the excited girl, she lay there waiting. Of course her door was locked, but the affair of the Winged Cartwheels a few months before had taught Dorothy that keys may be turned from the outside with a pair of small pincers. Her mind now set itself on the key in the door. In vain she listened for the warning click that would come when it turned in the lock. Now that she was lying in bed she began to discover how tired she was. It became harder and harder to stay awake.

She knew that she must have dozed, for without warning a light appeared, a golden circle on the center of the rug. Instantly she was wide awake and her hand beneath the blankets drew her throwing knife from its sheath. Through half-closed eyelids she made out a dark figure holding a flash light pointed toward the floor.

Then the glowing circle moved to the empty glass beside her bed, and Dorothy closed her eyes. For a moment it rested upon her face and she heard a low chuckle. Dorothy knew that voice. Her visitor was Laura Lawson.

The light swept away from her face. Mrs. Lawson touched the wall switch by the door and the bedroom sprang into light. The drug in the lemonade must have been a strong one, for it was evident that the intruder had no fear of her awakening. Without wasting another glance on Dorothy, Laura Lawson went to the wardrobe trunk and commenced a detailed inspection of its contents.

The woman’s back was turned, so Dorothy had no difficulty in watching her movements. Everything in the trunk was taken out, glanced at and put back exactly as it had been. This took some time, and it was fully half an hour before her hostess finished with the trunk. Next she overhauled the small travelling bag and the purse. Then the empty drawers of the dressing table and desk came under the woman’s eye. The pillows and cushions of the window seat were lifted. The rug was turned back. Every nook and cranny of the room and closet came under observation. Then she went into the bathroom.

“What under the shining canopy can she be looking for?” Dorothy marveled. “It can’t be the note I got tonight. She proposed the lemonade before that could have been written. I wonder if she’ll search the bed? She mustn’t find Flash – ”

When Laura Lawson returned to the bedroom, she saw that the sleeper had turned over and was now facing the wall. For a moment she gazed down on the girl, then her hand crept under the pillow. Finding nothing there, the covers were pulled back to the foot of the bed.

Dorothy felt the cold breeze from the open window blowing on her pajamaed body, but she did not move. Presently sheet, blankets and silk comfort were replaced and the woman left the bedside. Dorothy chuckled inwardly. Flash was still safe. She was lying on him.

Off went the light. Dorothy knew that Mrs. Lawson’s slippered feet would make no sound on the thick pile of the rug. She waited to hear the door open and close, but heard nothing. With her face to the wall, she could see nothing. The strain of lying motionless became nerve wracking. What was the woman doing anyhow? Slowly she rolled over again. So far as she could tell, the room was empty.

For what seemed an age Dorothy lay, listening. Except for the wind sighing through the bare trees outside her window, there was no other sound. She felt nervous and unpleasantly excited. She must know if the door had been left unlocked. Slipping out of bed she tiptoed across to it and tried the handle. The door did not give.

Suddenly she froze against the panels. A dim glow appeared on the opposite wall as the closet door swung slowly back, and outlined in the opening was the tall figure of Tunbridge.

Chapter X

SURPRISES

Dorothy’s experiences, since she had shopped for neckties for her father that morning had been quite enough to lay up the average girl for a week, and to wreck her nerves into the bargain. Laura Lawson’s appearance in her bedroom had strained tightened nerves to the breaking point.

The arrival of this second intruder was just too much. As the butler stepped out of the closet and started to close the door, Dorothy’s self-control snapped like a rubber band. She forgot that she was playing a part; that it might be suicidal to show her hand so early in the game. Fear gripped her throat. Had this man been sent to kill her? If not, then what was he doing, stealing into her room through a secret entrance like an assassin of the middle ages? Self-preservation bade her act. The consequences could take care of themselves.

“Stop!” The harsh whisper, as her hand dove for Flash, sounded like the voice of a stranger. “Move another step, and I’ll pin you to that door!” Flash was in her raised hand now, the extended blade reflecting the light in the closet as though the polished steel were glass.

She saw the man start in surprise and turn his head in her direction. As she was about to hurl the knife, Tunbridge found his voice.

“Ashton Sanborn sent me, Miss Dixon. Please don’t throw that knife.”

Gone was the English accent, and the pompous intonation of the British man servant. Tunbridge, if that were really his name, spoke the American Dorothy was accustomed to hear, the accents of the cultured New Englander. For the second time in her life, Dorothy fainted.

She awoke to find herself in bed. Tunbridge was beside it. She could just make out his tall, powerful figure in the darkness.

“Goodness – did I faint?” she said weakly.

“You certainly did, Miss Dixon.” His tone was little above a whisper. “Please don’t raise your voice – and drink this. I found the aromatic spirits of ammonia in the bathroom. You need something to steady you. No one is cast iron – you’ve been through a frightful lot today.”

Dorothy took the glass and drained it. Then she lay back on her pillow. “I got the scare of my life just now. Why didn’t Ashton Sanborn tell me about you, Mr. – ”

“Tunbridge is really my name, Miss Dixon. John Tunbridge, and very much at your service. I was afraid my rather abrupt appearance would startle you, and especially coming so soon after Mrs. Lawson’s – er – visit. I got a shock myself when I saw your white figure by the door just now, and all ready to split me with that knife, like – like a macaroon.” He chuckled, and removing the tray, sat down on the chair beside her bed.

“Oh, then you’ve seen Ashton Sanborn this evening, Mr. Tunbridge?”

“Heard from him, Miss Dixon. As you must know by now, I am a secret service operative and I am working under Mr. Sanborn. There isn’t time to go into detail now, but a couple of months ago, our department received an anonymous letter saying that Doctor Winn would bear watching. Shortly before that the Doctor had engaged Mrs. Lawson, who is an expert chemist by the way, to take charge of his laboratory. Her husband has been Doctor Winn’s secretary since last spring. We thought at that time that Mrs. Lawson might be the mysterious letter writer. Since then we’ve altered our opinion. Mr. Sanborn decided that inasmuch as Doctor Winn was working for the government it would be well to have a secret service man in the house. We prevailed upon the butler here to resign and I took his place.”

“Then Doctor Winn knows you’re a government detective?”

“No one in this house knows that, except you, Miss Dixon. The whole matter was arranged through an employment agency. Doctor Winn and the others here have no idea that I, like you, am simply playing a part.”

“Well, you’re certainly a splendid actor, Mr. Tunbridge.”

“Thank you, Miss Dixon. As you’ve no doubt discovered, acting, convincing acting, often plays a large part in our profession. You are doing brilliantly in that respect yourself. Mr. Sanborn thought, however, that it would be better if you did not know about me until the necessity arose. Mrs. Lawson, he knew would be watching you like a hawk when you arrived. If you had been aware of my identity, your position would only have been more difficult. She might have had her suspicions aroused in some way, which would have given you a wrong start from the beginning. I think you will realize tomorrow how hard it will be to treat me as though I were merely Tunbridge the butler.”

“Oh, I think you’re right. Tell me, how did you find out about the lemonade?”

“I overheard the Lawsons talking, yesterday. Made it my business in fact. It seems that Mrs. Lawson has had the idea that if Janet Jordan was only shamming sleep at that meeting, she would do her best to communicate with her father in some way. The natural thing to do would be to write a note and slip it in his hand or his pocket, when he came to see her. Martin Lawson was sure he would detect anything of the kind when he brought Jordan to say goodbye to Janet tonight at the flat. If not, the plan was to drug the girl with hot lemonade so that Mrs. Lawson could search her belongings for the note tonight.”

Dorothy nodded. “I watched her closely while she was in here, and so far as I could make out she didn’t find anything that interested her particularly. The Lawsons must have guessed wrong about Janet writing her father.”

“Well, no, they didn’t,” declared her new ally. “Janet wrote a letter, just as they surmised.”

“But where could it be?” asked Dorothy in a startled whisper, and sat bold upright in bed.

“Probably destroyed by this time,” Mr. Tunbridge chuckled. “There’s no need to worry on that score, Miss Dixon. When Ashton Sanborn spoke to your cousin this afternoon by means of Howard Bright’s headphone set, he learned that Janet proposed doing just what this clever pair here figured upon. Of course she had already written the note, and as there was no safe way to get rid of it in her room, he told her to take it with her when she left. And now if you’ll be good enough, I wish you’d tell me what happened after you took her place in the flat.”

Dorothy gave him a short sketch of her encounter with her uncle and Martin Lawson in Janet’s room, and of the conversation between the two men in the corridor afterward. “All the way up here,” she ended, “I pretended I had a grouch. Mr. Lawson tried to start a conversation several times, but he soon found it wasn’t much fun talking to himself and he gave it up as a bad job.”

“Excellent,” applauded the secret service man, “and quite in keeping with your behavior in the flat. You have done most remarkably well, Miss Dixon. Only – you won’t mind if I warn you not to let first success make you careless.”

“Do you really believe that these people mean to do away with me if they discover I am not what I appear to be, Mr. Tunbridge? It sounds a bit too melodramatic, don’t you think?”

“These Lawsons, husband and wife, are playing for gigantic stakes.” The detective’s voice, though barely audible was extremely grave. “They will stop at nothing. When crooks have at least two murders behind them, they’re not likely to stop at a third.”

“Then – then they are

not

what they pretend?”

“Certainly not. They’re a pair of high class European crooks named du Val.”

Dorothy shuddered. “And

murderers

!”

“Undoubtedly. They’re wanted both in England and in Austria for their crimes.”

“How did you find that out?”

“Oh, you see I recognized them when I arrived here, Miss Dixon.”

“But – but I can’t see why – why you didn’t arrest them then and there! You knew that they were after the secret of Doctor Winn’s new explosive, or whatever it is he has invented.”

“Yes, we realized that the formula for Doctor Winn’s explosive gas was the magnet that drew the du Vals to this house; but until today we had no idea how they proposed to dispose of the formula after stealing it.”

“I see. And now you realize that they probably intend to sell it to the organization of which my uncle is a member?”

“You are right, Miss Dixon.”

“Then why can’t you arrest the Lawsons now?”

“We can take the Lawsons at any time,” Tunbridge explained. “But we want to catch the ringleader of this organization. We know the group exists and for no good purpose, but what their definite object may be we still have no means of telling. We can’t arrest them on suspicion alone. Once they actually buy the formula from the Lawsons, it will be quite a different matter.”

She shook her head slowly. “But why hasn’t the formula been stolen before this? They’ve had plenty of opportunity, surely – ”

“Because it is not completed. At dinner tonight I heard the Doctor say that by tomorrow afternoon the work would be finished, and that he expected to take the formula to Washington the day after tomorrow.”

“Then you expect? – ”

“I expect that the Lawsons will make their attempt tomorrow night.”

“And where do I come in on this business, Mr. Tunbridge?”

“You are going to take the plans from Doctor Winn’s safe before the Lawsons get to it.”

She drew her breath sharply. “That’s a pretty large order – ”

“I know it, but – of course you’ll have the combination of the safe – ”

“Are you going to give it to me now?”

“Too dangerous. They are quite capable of searching your belongings again – or your person, for that matter – at any time. I’ll get it to you with exact instructions just as soon as the Doctor completes that blooming formula and locks it in the safe.”

“That’s all very well, Mr. Tunbridge. But has it occurred to you that if I steal this paper – I suppose it will be a paper? – ”

“Probably several of them – ”

“Well, if I take these papers before the Lawsons can get them, how are you going to arrest my uncle and the other men?”

“You,” directed Tunbridge, “will simply make a copy and replace the original documents where you found them. This is a safety-first move. We must have a copy in case the originals are destroyed.”

“It looks like a very complicated matter to me,” Dorothy admitted candidly. “Why not put the old gentleman wise? After all, it’s his formula, and if he made his own copy it would save us a possible run-in with the Lawsons, and – ”

Mr. Tunbridge stood up. “Perhaps you’re right,” he said, making a brave attempt to stifle a yawn, “but Doctor Winn would never agree to it. For a scientist who dabbles in high explosives, he’s the most nervous man I’ve ever met. He’d give the whole show away. No, that’s out of the question. Doctor Winn must be kept in ignorance of the whole proceeding. And now – ” a yawn got the better of him this time – “and now to bed. You need sleep even more than advice just now. Good night, or rather, good morning, Miss Dixon. Pleasant dreams, I hope.”

He started toward the door and Dorothy sprang out of bed and reached for her dressing gown.

“I want to see that secret passage, Mr. Tunbridge,” she said in a low tone.

“Oh, yes, come along.” He opened the door and stepped inside the closet. “It works this way. Press your foot on the board in the farthest right hand corner, like this, and a panel in the back wall slides up – like that – ”

Dorothy stared at the gaping black hole, then as the detective-butler snapped on his flashlight she saw that a narrow circular staircase led downward in the wall.

“That stair curves down to the ground floor,” he explained. “It comes out through the side wall inside the big fireplace in the hall. To open the panel down there you press a button under the left-hand corner of the mantel. To close either panel you simply put it down, once you’re inside.”

“Are there any more of these passages in the walls?”

“Very likely, but I haven’t found them yet. Winncote is an exact copy of the Doctor’s ancestral home in Wales. Those old houses were honeycombed with priest holes, secret passages and whatnot. And Doctor Winn had his architect copy the original Winncote across the water down to the last stone, with modern improvements such as bathrooms and steam heat, added.”

“Funny old fellow, isn’t he?” commented Dorothy sleepily. “Then I’m simply to carry on until I hear from you again?”

“That’s right. But whatever you do, watch your step with the Lawson woman. She is fully as heartless as she is beautiful. If you had never heard of that meeting in the Jordans’ flat, it would be much better for you. She will try to trap you, so please be on your guard continually. Well, good night, again.”

“Good night, Mr. Tunbridge.”

The panel in the back wall of the closet sl