"What on earth are you doing?" demanded Tuppence, as she entered the inner sanctum of the International Detective Agency-(Slogan-Blunt's Brilliant Detectives) and discovered her lord and master prone on the floor in a sea of books.

Tommy struggled to his feet.

"I was trying to arrange these books on the top shelf of that cupboard," he complained. "And the damned chair gave way."

"What are they, anyway?" asked Tuppence, picking up a volume. "'The Hound of the Baskervilles.' I wouldn't mind reading that again some time."

"You see the idea?" said Tommy, dusting himself with care. "Half hours with the Great Masters-that sort of thing. You see, Tuppence, I can't help feeling that we are more or less amateurs at this business-of course amateurs in one sense we cannot help being, but it would do no harm to acquire the technique, so to speak. These books are detective stories by the leading masters of the art. I intend to try different styles, and compare results."

"H'm," said Tuppence. "I often wonder how those detectives would have got on in real life." She picked up another volume. "You'll find a difficulty in being a Thorndyke. You've no medical experience, and less legal, and I never heard that science was your strong point."

"Perhaps not," said Tommy. "But at any rate I've bought a very good camera, and I shall photograph footprints and enlarge the negatives and all that sort of thing. Now, mon ami, use your little grey cells-what does this convey to you?"

He pointed to the bottom shelf of the cupboard. On it lay a somewhat futuristic dressing gown, a turkish slipper, and a violin.

"Obvious, my dear Watson," said Tuppence.

"Exactly," said Tommy. "The Sherlock Holmes touch."

He took up the violin and drew the bow idly across the strings, causing Tuppence to give a wail of agony.

At that moment the buzzer rang on the desk, a sign that a client had arrived in the outer office and was being held in parley by Albert, the office boy.

Tommy hastily replaced the violin in the cupboard and kicked the books behind the desk.

"Not that there's any great hurry," he remarked. "Albert will be handing them out the stuff about my being engaged with Scotland Yard on the phone. Get into your office and start typing, Tuppence. It makes the office sound busy and active. No, on second thoughts, you shall be taking notes in shorthand from my dictation. Let's have a look before we get Albert to send the victim in."

They approached the peephole which had been artistically contrived so as to command a view of the outer office.

The client was a girl of about Tuppence's age, tall and dark with a rather haggard face and scornful eyes.

"Clothes cheap and striking," remarked Tuppence. "Have her in, Tommy."

In another minute the girl was shaking hands with the celebrated Mr. Blunt, whilst Tuppence sat by with eyes demurely downcast, and pad and pencil in hand.

"My confidential secretary, Miss Robinson," said Mr. Blunt with a wave of the hand. "You may speak freely before her." Then he lay back for a minute, half closed his eyes and remarked in a tired tone: "You must find traveling in a bus very crowded at this time of day."

"I came in a taxi," said the girl.

"Oh!" said Tommy aggrieved. His eyes rested reproachfully on a blue bus ticket protruding from her glove. The girl's eyes followed his glance, and she smiled and drew it out.

"You mean this? I picked it up on the pavement. A little neighbor of ours collects them."

Tuppence coughed, and Tommy threw a baleful glare at her.

"We must get to business," he said briskly. "You are in need of our services, Miss-?"

"Kingston Bruce is my name," said the girl. "We live at Wimbledon. Last night a lady who is staying with us lost a valuable pink pearl. Mr. St. Vincent was also dining with us, and during dinner he happened to mention your firm. My mother sent me off to you this morning to ask you if you would look into the matter for us."

The girl spoke sullenly, almost disagreeably. It was clear as daylight that she and her mother had not agreed over the matter. She was here under protest.

"I see," said Tommy, a little puzzled. "You have not called in the police?"

"No," said Miss Kingston Bruce, "we haven't. It would be idiotic to call in the police and then find that the silly thing had rolled under the fireplace, or something like that."

"Oh!" said Tommy. "Then the jewel may only be lost after all?"

Miss Kingston Bruce shrugged her shoulders.

"People make such a fuss about things," she murmured.

Tommy cleared his throat.

"Of course," he said doubtfully. "I am extremely busy just now-"

"I quite understand," said the girl rising to her feet. There was a quick gleam of satisfaction in her eyes which Tuppence, for one, did not miss.

"Nevertheless," continued Tommy, "I think I can manage to run down to Wimbledon. Will you give me the address, please?"

"The Laurels, Edgeworth Road."

"Make a note of it, please, Miss Robinson."

Miss Kingston Bruce hesitated, then said rather ungraciously:

"We'll expect you then. Good morning."

"Funny girl," said Tommy. "I couldn't quite make her out."

"I wonder if she stole the thing herself," remarked Tuppence meditatively. "Come on, Tommy, let's put away these books and take the car and go down there. By the way, who are you going to be, Sherlock Holmes still?"

"I think I need practice for that," said Tommy. "I came rather a cropper over that bus ticket, didn't I?"

"You did," said Tuppence. "If I were you I shouldn't try too much on that girl-she's as sharp as a needle. She's unhappy too, poor devil."

"I suppose you know all about her already," said Tommy with sarcasm, "simply from looking at the shape of her nose!"

"I'll tell you my idea of what we shall find at The Laurels," said Tuppence, quite unmoved. "A household of snobs, very keen to move in the best society; the father, if there is a father, is sure to have a military title. The girl falls in with their way of life and despises herself for doing so."

Tommy took a last look at the books now neatly ranged upon a shelf.

"I think," he said thoughtfully, "that I shall be Thorndyke to-day."

"I shouldn't have thought there was anything medico-legal about this case," remarked Tuppence.

"Perhaps not," said Tommy. "But I'm simply dying to use that new camera of mine! It's supposed to have the most marvelous lens that ever was or ever could be."

"I know those kind of lenses," said Tuppence. "By the time you've adjusted the shutter and stopped down and calculated the exposure and kept your eyes on the spirit level, your brain gives out, and you yearn for the simple Brownie."

"Only an unambitious soul is content with the simple Brownie."

"Well, I bet I shall get better results with it than you will."

Tommy ignored this challenge.

"I ought to have a 'Smoker's Companion,' " he said regretfully. "I wonder where one buys them?"

"There's always the patent corkscrew Aunt Araminta gave you last Xmas," said Tuppence helpfully.

"That's true," said Tommy. "A curious looking engine of destruction I thought it at the time, and rather a humorous present to get from a strictly teetotal aunt."

"I," said Tuppence, "shall be Polton."

Tommy looked at her scornfully.

"Polton indeed. You couldn't begin to do one of the things that he does."

"Yes, I can," said Tuppence. "I can rub my hands together when I'm pleased. That's quite enough to get on with. I hope you're going to take plaster casts of footprints?"

Tommy was reduced to silence. Having collected the corkscrew they went round to the garage, got out the car and started for Wimbledon.

The Laurels was a big house. It ran somewhat to gables and turrets, had an air of being very newly painted, and was surrounded with neat flower beds filled with scarlet geraniums.

A tall man with a close cropped white moustache, and an exaggeratedly martial bearing opened the door before Tommy had time to ring.

"I've been looking out for you," he explained fussily. "Mr. Blunt, is it not? I am Colonel Kingston Bruce. Will you come into my study?"

He led them into a small room at the back of the house.

"Young St. Vincent was telling me wonderful things about your firm. I've noticed your advertisements myself. This guaranteed twenty-four hours service of yours-a marvelous notion. That's exactly what I need."

Inwardly anathematizing Tuppence for her irresponsibility in inventing this brilliant detail, Tommy replied: "Just so Colonel."

"The whole thing is most distressing, sir, most distressing."

"Perhaps you would kindly give me the facts," said Tommy, with a hint of impatience.

"Certainly I will-at once. We have at the present moment staying with us a very old and dear friend of ours, Lady Laura Barton. Daughter of the late Earl of Carrowway. The present Earl, her brother, made a striking speech in the House of Lords the other day. As I say, she is an old and dear friend of ours. Some American friends of mine who have just come over, the Hamilton Betts, were most anxious to meet her. 'Nothing easier,' I said. 'She is staying with me now. Come down for the week-end.' You know what Americans are about titles, Mr. Blunt."

"And others besides Americans sometimes, Colonel Kingston Bruce."

"Alas! only too true, my dear sir. Nothing I hate more than a snob. Well, as I was saying, the Betts came down for the week-end. Last night-we were playing Bridge at the time-the clasp of a pendant Mrs. Hamilton Betts was wearing broke, so she took it off and laid it down on a small table, meaning to take it upstairs with her when she went. This, however, she forgot to do. I must explain, Mr. Blunt, that the pendant consisted of two small diamond wings, and a big pink pearl depending from them. The pendant was found this morning lying where Mrs. Betts had left it, but the pearl, a pearl of enormous value, had been wrenched off."