The drapers, during sale time, invariably employ detectives in plain clothes to look after their goods, but in this case it was the customers who were robbed, and the detectives, attentive to every attempt at “shop-lifting,” had had no eyes for the more subtle thief.

I had already noticed Miss Rosie Campbell’s keen look of excitement whenever the pseudo Mrs. Stone discussed these cases with her. I was not a bit surprised, therefore, when, one afternoon at about tea-time, my dear lady came home from her habitual walk, and, at the top of her shrill voice, called out to me from the hall:

“Mary! Mary! They’ve got the man of the shop robberies. He’s given the silly police the slip this time, but they know who he is now, and I suppose they’ll get him presently. ”Tisn’t anybody I know,“ she added, with that harsh, common laugh which she had adopted for her part.

I had come out of the room in response to her call, and was standing just outside our own sitting-room door. Mrs. Tredwen, too, bedraggled and unkempt, as usual, had sneaked up the area steps, closely followed by Ermyntrude.

But on the half-landing just above us the trembling figure of Rosie Campbell, with scared white face and dilated eyes, looked on the verge of a sudden fall.

Still talking shrilly and volubly, Lady Molly ran up to her, but Campbell met her half-way, and the pseudo Mrs. Stone, taking vigorous hold of her wrist, dragged her into our own sitting-room.

“Pull yourself together, now,” she said with rough kindness. “That owl Tredwen is listening, and you needn’t let her know too much. Shut the door, Mary. Lor” bless you, m’dear, I’ve gone through worse scares than these. There! You just lie down on this sofa a bit. My niece’ll make you a cup o‘ tea; and I’ll go and get an evening paper, and see what’s going on. I suppose you are very interested in the shop-robbery man, or you wouldn’t have took on so.“

Without waiting for Campbell ’s contradiction to this statement, Lady Molly flounced out of the house.

Miss Campbell hardly spoke during the next ten minutes that she and I were left alone together. She lay on the sofa with eyes wide open, staring up at the ceiling, evidently still in a great state of fear.

I had just got tea ready when Lady Molly came back. She had an evening paper in her hand, but threw this down on the table directly she came in. “

“I could only get an early edition,” she said breathlessly, “and the silly thing hasn’t got anything in it about the matter.”

She drew near to the sofa, and, subduing the shrillness of her voice, she whispered rapidly, bending down towards Campbell:

“There’s a man hanging about at the corner down there. No, no; it’s not the police,” she added quickly, in response to the girl’s sudden start of alarm. “Trust me, my dear, for knowing a ”tec when I see one! Why, I’d smell one half a mile off. No; my opinion is that it’s your man, my dear, and that he’s in a devil of a hole.“

“Oh! He oughtn’t to come here,” ejaculated Campbell in great alarm. “He’ll get me into trouble and do himself no good. He’s been a fool!” she added, with a fierceness wholly unlike her usual demure placidity, “getting himself caught like that. Now I suppose we shall have to hook it – if there’s time.”

“Can I do anything to help you?” asked the pseudo Mrs. Stone. “You know I’ve been through all this myself, when they was after Mr. Stone. Or perhaps Mary could do something.”

“Well, yes,” said the girl, after a slight pause, during which she seemed to be gathering her wits together. “I’ll write a note, and you shall take it, if you will, to a friend of mine – a lady who lives in the Cromwell Road. But if you still see a man lurking about at the corner of the street, then, just as you pass him, say the word ”Campbell,“ and if he replies ‘Rosie,” then give him the note. Will you do that?“

“Of course I will, my dear. Just you leave it all to me.”

And the pseudo Mrs. Stone brought ink and paper and placed them on the table. Rosie Campbell wrote a brief note, and then fastened it down with a bit of sealing-wax before she handed it over to Lady Molly. The note was addressed to Miss Marvell, Scotia Hotel, Cromwell Road.

“You understand?” she said eagerly. “Don’t give the note to the man unless he says ”Rosie‘ in reply to the word “ Campbell.”“

“All right – all right!” said Lady Molly, slipping the note into her reticule. “And you go up to your room, Miss Campbell; it’s no good giving that old fool Tredwen too much to gossip about.”

Rosie Campbell went upstairs, and presently my dear lady and I were walking rapidly down the badly lighted street.

“Where is the man?” I whispered eagerly as soon as we were out of earshot of No. 34.

“There is no man,” replied Lady Molly, quickly.

“But the West End shop thief?” I asked.

“He hasn’t been caught yet, and won’t be either, for he is far too clever a scoundrel to fall into an ordinary trap.”

She did not give me time to ask further questions, for presently, when we had reached Reporton Square, my dear lady handed me the note written by Campbell, and said:

“Go straight on to the Scotia Hotel, and ask for Miss Marvell; send up the note to her, but don’t let her see you, as she knows you by sight. I must see the chief first, and will be with you as soon as possible. Having delivered the note, you must hang about outside as long as you can. Use your wits; she must not leave the hotel before I see her.”

There was no hansom to be got in this elegant quarter of the town, so, having parted from my dear lady, I made for the nearest Underground station, and took a train for South Kensington.

Thus it was nearly seven o’clock before I reached the Scotia. In answer to my inquiries for Miss Marvell, I was told that she was ill in bed and could see no one. I replied that I had only brought a note for her, and would wait for a reply.

Acting on my dear lady’s instructions, I was as slow in my movements as ever I could be, and was some time in finding the note and handing it to a waiter, who then took it upstairs.

Presently he returned with the message: “Miss Marvell says there is no answer.”

Whereupon I asked for pen and paper at the office, and wrote the following brief note on my own responsibility, using my wits as my dear lady had bidden me to do.

Please, madam, I wrote, will you send just a line to Miss Rosie Campbell? She seems very upset and frightened at some news she has had.

Once more the waiter ran upstairs, and returned with a sealed envelope, which I slipped into my reticule.

Time was slipping by very slowly. I did not know how long I should have to wait about outside in the cold, when, to my horror, I heard a hard voice, with a marked Scotch accent, saying:

“I am going out, waiter, and shan’t be back to dinner. Tell them to lay a little cold supper upstairs in my room.”

The next moment Miss Marvell, with coat, hat, and veil, was descending the stairs.

My plight was awkward. I certainly did not think it safe to present myself before the lady; she would undoubtedly recollect my face. Yet I had orders to detain her until the appearance of Lady Molly.

Miss Marvell seemed in no hurry. She was putting on her gloves as she came downstairs. In the hall she gave a few more instructions to the porter, whilst I, in a dark corner in the background, was vaguely planning an assault or an alarm of fire.

Suddenly, at the hotel entrance, where the porter was obsequiously holding open the door for Miss Marvell to pass through, I saw the latter’s figure stiffen; she took one step back as if involuntarily, then, equally quickly, attempted to dart across the threshold, on which a group – composed of my dear lady, of Saunders, and of two or three people scarcely distinguishable in the gloom beyond – had suddenly made its appearance.

Miss Marvell was forced to retreat into the hall; already I had heard Saunders’s hurriedly whispered words: