"Better not go in just yet," said Dymchurch as he and Tommy hurried into Haleham Street. "You've got the key all right?"

Tommy nodded.

"Then what about a bite of dinner? It's early, but there's a little place here right opposite. We'll get a table by the window, so that we can watch the place all the time."

They had a very welcome little meal, in the manner the detective had suggested. Tommy found Inspector Dymchurch quite an entertaining companion. Most of his official work had lain amongst international spies, and he had tales to tell which astonished his simple listener.

They remained in the little Restaurant until eight o'clock when Dymchurch suggested a move.

"It's quite dark now, sir," he explained. "We shall be able to slip in without anyone being the wiser."

It was, as he said, quite dark. They crossed the road looked quickly up and down the deserted street, and slipped inside the entrance. Then they mounted the stairs, and Tommy inserted his key in the lock of the outer office.

Just as he did so, he heard, as he thought, Dymchurch whistle beside him.

"What are you whistling for?" he asked sharply.

"I didn't whistle," said Dymchurch, very much astonished, "I thought you did."

"Well, someone-" began Tommy.

He got no further. Strong arms seized him from behind, and before he could cry out, a pad of something sweet and sickly was pressed over his mouth and nose.

He struggled valiantly, but in vain. The chloroform did its work. His head began to whirl and the floor heaved up and down in front of him. Choking, he lost consciousness…

He came to himself painfully but in full possession of his faculties. The chloroform had been only a whiff. They had kept him under long enough to force a gag into his mouth and ensure that he did not cry out.

When he came to himself, he was half lying, half sitting, propped against the wall in a corner of his own inner office. Two men were busily turning out the contents of the desk, and ransacking the cupboards, and as they worked they cursed freely.

"Swelp me, guvnor," said the taller of the two hoarsely, "we've turned the whole bloody place upside down and inside out. It's not there."

"It must be here," snarled the other. "It isn't on him. And there's no other place it can be."

As he spoke he turned, and to Tommy's utter amazement he saw that the last speaker was none other than Inspector Dymchurch. The latter grinned when he saw Tommy's astonished face.

"So our young friend is awake again," he said. "And a little surprised-yes, a little surprised. But it was so simple. We suspect that all is not as it should be with the International Detective Agency. I volunteer to find out if that is so, or not. If the new Mr. Blunt is indeed a spy, he will be suspicious, so I send first my dear old friend Carl Bauer. Carl is told to act suspiciously and pitch an improbable tale. He does so, and then I appear on the scene. I use the name of Inspector Marriot to gain confidence. The rest is easy."

He laughed.

Tommy was dying to say several things, but the gag in his mouth prevented him. Also, he was dying to do several things -mostly with his hands and feet-but alas, that too had been attended to. He was securely bound.

The thing that amazed him most was the astounding change in the man standing over him. As Inspector Dymchurch, the fellow had been a typical Englishman. Now, no one could have mistaken him for a moment for anything but a well educated foreigner who talked English perfectly without trace of accent.

"Coggins, my good friend," said the erstwhile Inspector, addressing his ruffianly looking associate. "Take your life preserver and stand by the prisoner. I am going to remove the gag. You understand, my dear Mr. Blunt, do you not, that is would be criminally foolish on your part to cry out? But I am sure you do. For your age, you are quite an intelligent lad."

Very deftly he removed the gag, and stepped back.

Tommy eased his stiff jaws, rolled his tongue round his mouth, swallowed twice-and said nothing at all.

"I congratulate you on your restraint," said the other. "You appreciate the position, I see. Have you nothing at all to say?"

"What I have to say will keep," said Tommy. "And it won't spoil by waiting."

"Ah! What I have to say will not keep. In plain English, Mr. Blunt, where is that letter?"

"My dear fellow, I don't know," said Tommy cheerfully. "I haven't got it. But you know that as well as I do. I should go on looking about if I were you. I like to see you and friend Coggins playing Hide and Seek together."

The other's face darkened.

"You are pleased to be flippant, Mr. Blunt. You see that square box over there. That is Coggins' little outfit. In it there is vitriol… yes, vitriol… and irons that can be heated in the fire, so that they are red hot and burn…"

Tommy shook his head sadly.

"An error in diagnosis," he murmured. "Tuppence and I labelled this adventure wrong. It's not a Clubfoot story. It's a Bull Dog Drummond, and you are the inimitable Carl Peterson."

"What is this nonsense you are talking?" snarled the other.

"Ah!" said Tommy. "I see you are unacquainted with the Classics. A pity."

"Ignorant fool? Will you do what we want or will you not? Shall I tell Coggins to get out his tools and begin?"

"Don't be so impatient," said Tommy. "Of course I'll do what you want, as soon as you tell me what it is. You don't suppose I want to be carved up like a filleted sole and fried on a gridiron? I loathe being hurt."

Dymchurch looked at him in contempt.

"Gott! What cowards are these English."

"Common sense, my dear fellow, merely common sense. Leave the vitriol alone, and let us come down to brass tacks."

"I want the letter."

"I've already told you I haven't got it."

"We know that-we also know who must have it. The girl."

"Very possibly you're right," said Tommy. "She may have slipped it into her handbag when your pal Carl startled us."

"Oh, you do not deny. That is wise. Very good, you will write to this Tuppence, as you call her, bidding her bring the letter here immediately."

"I can't do that," began Tommy.

The other cut in before he had finished the sentence.

"Ah! You can't? Well, we shall soon see. Coggins!"

"Don't be in such a hurry," said Tommy. "And do wait for the end of the sentence. I was going to say that I can't do that unless you untie my arms. Hang it all, I'm not one of those freaks who can write with their noses or their elbows."

"You are willing to write, then?"

"Of course. Haven't I been telling you so all along? I'm all out to be pleasant and obliging. You won't do anything unkind to Tuppence, of course. I'm sure you won't. She's such a nice girl."

"We only want the letter," said Dymchurch, but there was a singularly unpleasant smile on his face.

At a nod from him, the brutal Coggins knealt down and unfastened Tommy's arms. The latter swung them to and fro.

"That's better," he said cheerfully. "Will kind Coggins hand me my fountain pen? It's on the table, I think, with my other miscellaneous property."

Scowling, the man brought it to hire, and provided a sheet of paper.

"Be careful what you say," Dymchurch said menacingly.

"We leave it to you, but failure means-death-and slow death at that."

"In that case," said Tommy, "I will certainly do my best."

He reflected a minute or two, then began to scribble rapidly.

"How will this do?" he asked, handing over the completed epistle.

Dear Tuppence,

Can you come along at once and bring that blue letter

with you? We want to decode it here and now.

In haste

Francis

"Francis?" queried the bogus Inspector, with lifted eyebrows. "Was that the name she called you?"

"As you weren't at my christening," said Tommy, "I don't suppose you can know whether it's my name or not. But I think the cigarette case you took from my pocket is a pretty good proof that I'm speaking the truth."

The other stepped over to the table and took up the case, read "Francis from Tuppence," with a faint grin and laid it down again.

"I am glad to find you are behaving so sensibly," he said. "Coggins, give that note to Vassily. He is on guard outside. Tell him to take it at once."

The next twenty minutes passed slowly, the ten minutes after that more slowly still. Dymchurch was striding up and down with a face that grew darker and darker. Once he turned menacingly on Tommy.

"If you have dared to double cross us…" he growled.

"If we'd had a pack of cards here, we might have had a game of picquet to pass the time," drawled Tommy. "Women always keep one waiting. I hope you're not going to be unkind to little Tuppence when she comes?"

"Oh! no," said Dymchurch. "We shall arrange for you to go to the same place-together."

"Will you, you swine," said Tommy under his breath.

Suddenly there was a stir in the outer office. A man whom Tommy had not yet seen poked his head in and growled something in Russian.

"Good," said Dymchurch. "She is coming-and coming alone."

For a moment a faint anxiety caught at Tommy's heart.

The next minute he heard Tuppence's voice.

"Oh! there you are, Inspector Dymchurch. I've brought the letter. Where is Francis?"

With the last words she came through the door, and Vassily sprang on her from behind, clapping his hand over her mouth. Dymchurch tore the handbag from her grasp, and turned over its contents in a frenzied search.

Suddenly he uttered an ejaculation of delight and held up a blue envelope with a Russian stamp on it. Coggins gave a hoarse shout.

And just in that minute of triumph, the other door, the door into Tuppence's own office, opened noiselessly and Inspector Marriott and two men armed with revolvers stepped into the room, with the sharp command: "Hands Up!"

There was no fight. The others were taken at a hopeless disadvantage. Dymchurch's automatic lay on the table, and the two others were not armed.