SIR James's words came like a bomb-shell. Both girls looked equally puzzled. The lawyer went across to his desk, and returned with a small newspaper cutting, which he handed to Jane. Tuppence read it over her shoulder. Mr. Carter would have recognized it. It referred to the mysterious man found dead in New York.

"As I was saying to Miss Tuppence," resumed the lawyer, "I set to work to prove the impossible possible. The great stumbling-block was the undeniable fact that Julius Hersheimmer was not an assumed name. When I came across this paragraph my problem was solved. Julius Hersheimmer set out to discover what had become of his cousin. He went out West, where he obtained news of her and her photograph to aid him in his search. On the eve of his departure from New York he was set upon and murdered. His body was dressed in shabby clothes, and the face disfigured to prevent identification. Mr. Brown took his place. He sailed immediately for England. None of the real Hersheimmer's friends or intimates saw him before he sailed—though indeed it would hardly have mattered if they had, the impersonation was so perfect. Since then he had been hand and glove with those sworn to hunt him down. Every secret of theirs has been known to him. Only once did he come near disaster. Mrs. Vandemeyer knew his secret. It was no part of his plan that that huge bribe should ever be offered to her. But for Miss Tuppence's fortunate change of plan, she would have been far away from the flat when we arrived there. Exposure stared him in the face. He took a desperate step, trusting in his assumed character to avert suspicion. He nearly succeeded—but not quite."

"I can't believe it," murmured Jane. "He seemed so splendid."

"The real Julius Hersheimmer was a splendid fellow! And Mr. Brown is a consummate actor. But ask Miss Tuppence if she also has not had her suspicions."

Jane turned mutely to Tuppence. The latter nodded.

"I didn't want to say it, Jane—I knew it would hurt you. And, after all, I couldn't be sure. I still don't understand why, if he's Mr. Brown, he rescued us."

"Was it Julius Hersheimmer who helped you to escape?"

Tuppence recounted to Sir James the exciting events of the evening, ending up: "But I can't see why!"

"Can't you? I can. So can young Beresford, by his actions. As a last hope Jane Finn was to be allowed to escape—and the escape must be managed so that she harbours no suspicions of its being a put-up job. They're not averse to young Beresford's being in the neighbourhood, and, if necessary, communicating with you. They'll take care to get him out of the way at the right minute. Then Julius Hersheimmer dashes up and rescues you in true melodramatic style. Bullets fly—but don't hit anybody. What would have happened next? You would have driven straight to the house in Soho and secured the document which Miss Finn would probably have entrusted to her cousin's keeping. Or, if he conducted the search, he would have pretended to find the hiding-place already rifled. He would have had a dozen ways of dealing with the situation, but the result would have been the same. And I rather fancy some accident would have happened to both of you. You see, you know rather an inconvenient amount. That's a rough outline. I admit I was caught napping; but somebody else wasn't."

"Tommy," said Tuppence softly.

"Yes. Evidently when the right moment came to get rid of him—he was too sharp for them. All the same, I'm not too easy in my mind about him."

"Why?"

"Because Julius Hersheimmer is Mr. Brown," said Sir James dryly. "And it takes more than one man and a revolver to hold up Mr. Brown...."

Tuppence paled a little.

"What can we do?"

"Nothing until we've been to the house in Soho. If Beresford has still got the upper hand, there's nothing to fear. If otherwise, our enemy will come to find us, and he will not find us unprepared!" From a drawer in the desk, he took a service revolver, and placed it in his coat pocket.

"Now we're ready. I know better than even to suggest going without you, Miss Tuppence——"

"I should think so indeed!"

"But I do suggest that Miss Finn should remain here. She will be perfectly safe, and I am afraid she is absolutely worn out with all she has been through."

But to Tuppence's surprise Jane shook her head.

"No. I guess I'm going too. Those papers were my trust. I must go through with this business to the end. I'm heaps better now anyway."

Sir James's car was ordered round. During the short drive Tuppence's heart beat tumultuously. In spite of momentary qualms of uneasiness respecting Tommy, she could not but feel exultation. They were going to win!

The car drew up at the corner of the square and they got out. Sir James went up to a plain-clothes man who was on duty with several others, and spoke to him. Then he rejoined the girls.

"No one has gone into the house so far. It is being watched at the back as well, so they are quite sure of that. Anyone who attempts to enter after we have done so will be arrested immediately. Shall we go in?"

A policeman produced a key. They all knew Sir James well. They had also had orders respecting Tuppence. Only the third member of the party was unknown to them. The three entered the house, pulling the door to behind them. Slowly they mounted the rickety stairs. At the top was the ragged curtain hiding the recess where Tommy had hidden that day. Tuppence had heard the story from Jane in her character of "Annette." She looked at the tattered velvet with interest. Even now she could almost swear it moved—as though some one was behind it. So strong was the illusion that she almost fancied she could make out the outline of a form.... Supposing Mr. Brown—Julius—was there waiting....

Impossible of course! Yet she almost went back to put the curtain aside and make sure....

Now they were entering the prison room. No place for anyone to hide here, thought Tuppence, with a sigh of relief, then chided herself indignantly. She must not give way to this foolish fancying—this curious insistent feeling that Mr. Brown was in the house.... Hark! what was that? A stealthy footstep on the stairs? There was some one in the house! Absurd! She was becoming hysterical.

Jane had gone straight to the picture of Marguerite. She unhooked it with a steady hand. The dust lay thick upon it, and festoons of cobwebs lay between it and the wall. Sir James handed her a pocket-knife, and she ripped away the brown paper from the back.... The advertisement page of a magazine fell out. Jane picked it up. Holding apart the frayed inner edges she extracted two thin sheets covered with writing!

No dummy this time! The real thing!

"We've got it," said Tuppence. "At last...."

The moment was almost breathless in its emotion. Forgotten the faint creakings, the imagined noises of a minute ago. None of them had eyes for anything but what Jane held in her hand.

Sir James took it, and scrutinized it attentively.

"Yes," he said quietly, "this is the ill-fated draft treaty!"

"We've succeeded," said Tuppence. There was awe and an almost wondering unbelief in her voice.

Sir James echoed her words as he folded the paper carefully and put it away in his pocket-book, then he looked curiously round the dingy room.

"It was here that our young friend was confined for so long, was it not?" he said. "A truly sinister room. You notice the absence of windows, and the thickness of the close-fitting door. Whatever took place here would never be heard by the outside world."

Tuppence shivered. His words woke a vague alarm in her. What if there was some one concealed in the house? Some one who might bar that door on them, and leave them to die like rats in a trap? Then she realized the absurdity of her thought. The house was surrounded by police who, if they failed to reappear, would not hesitate to break in and make a thorough search. She smiled at her own foolishness—then looked up with a start to find Sir James watching her. He gave her an emphatic little nod.

"Quite right, Miss Tuppence. You scent danger. So do I. So does Miss Finn."

"Yes," admitted Jane. "It's absurd—but I can't help it."

Sir James nodded again.

"You feel—as we all feel— the presence of Mr. Bown. Yes"—as Tuppence made a movement—"not a doubt of it— Mr. Brown is here...."

"In this house?"

"In this room.... You don't understand? I am Mr. Brown...."

Stupefied, unbelieving, they stared at him. The very lines of his face had changed. It was a different man who stood before them. He smiled a slow cruel smile.

"Neither of you will leave this room alive! You said just now we had succeeded. I have succeeded! The draft treaty is mine." His smile grew wider as he looked at Tuppence. "Shall I tell you how it will be? Sooner or later the police will break in, and they will find three victims of Mr. Brown—three, not two, you understand, but fortunately the third will not be dead, only wounded, and will be able to describe the attack with a wealth of detail! The treaty? It is in the hands of Mr. Brown. So no one will think of searching the pockets of Sir James Peel Edgerton!"

He turned to Jane.

"You outwitted me. I make my acknowledgments. But you will not do it again."

There was a faint sound behind him, but, intoxicated with success, he did not turn his head.

He slipped his hand into his pocket.

"Checkmate to the Young Adventurers," he said, and slowly raised the big automatic.

But, even as he did so, he felt himself seized from behind in a grip of iron. The revolver was wrenched from his hand, and the voice of Julius Hersheimmer said drawlingly:

"I guess you're caught redhanded with the goods upon you."

The blood rushed to the K.C.'s face, but his self-control was marvellous, as he looked from one to the other of his two captors. He looked longest at Tommy.

"You," he said beneath his breath. "You! I might have known."

Seeing that he was disposed to offer no resistance, their grip slackened. Quick as a flash his left hand, the hand which bore the big signet ring, was raised to his lips....

"'Ave, Cæsar! te morituri salutant,'" he said, still looking at Tommy.

Then his face changed, and with a long convulsive shudder he fell forward in a crumpled heap, whilst an odour of bitter almonds filled the air.