Ivy blinked.

“She didn’t want anyone to know,” she said.

Miss Silver said, “No, I suppose not.” She looked at Ivy very kindly. “But it does not matter now.”

Ivy stood with her back to the sink, gripping the edge of it with her strong bony hands.

“What’s it got to do with you? I never said a word-I swear I didn’t. I never told no one. She was kind to Glad and me when we were kids. She used to let us watch her dress-help her on with her wings. She was in an act called The Fairy Butterfly, and she looked lovely. She didn’t want no one to know about us knowing each other. What does it matter now anyhow? She’s dead.”

Miss Silver said in her kindest voice,

“No, it doesn’t matter now. I think you had better tell me about it. She got you to come here to Mrs. Underwood, didn’t she?”

Ivy stared. She would have backed away if there had been anywhere to go, but the sink held her.

“How do you know?” she said in a frightened whisper.

Miss Silver took the success of a chance shot equably.

“You met her. Was it by accident? It is always pleasant when one runs up against an old friend like that. And she told you she had taken a flat here, and suggested that you should apply for Mrs. Underwood’s place?”

Ivy nodded. It was like being at the dentist’s, only worse. All the things she wouldn’t have told anyone were being pulled out of her one by one. Her thoughts raced to and fro, looking for a place to hide themselves. Her sharp Cockney mind came to the rescue. “Tell her something-quick! She won’t stop till you do. Tell her enough to make her stop, and she’ll think she’s got the lot. Coo-she’s a one!” She blinked again and said in a breathless voice,

“You didn’t arf give me a start, miss. However did you know?”

Miss Silver made no answer to that. She asked a question instead.

“Do you really walk in your sleep?”

This was awful. It took the rest of Ivy’s breath away. She began to feel as if she hadn’t any clothes on and Miss Silver’s eyes were looking right through her to her bones. She gasped and said,

“I did when I was a kid.”

“Have you walked in your sleep since you came here?”

“I might ha’ done.”

Miss Silver shook her head in slight but kind reproof.

“I think not. Mrs. Underwood locks the front door and takes the key into her room at night, does she not? I think you have been getting out of your window and walking along the ledge that runs round the house until you came to the fire-escape. Only someone who had had an acrobat’s training would have attempted such a thing, but it would not be difficult for you. I expect you rather enjoyed it. I notice that a ledge runs round the house on a level with the windows of each floor, so you had only to go up the fire-escape in order to reach Miss Roland’s flat. I see that the escape comes up beside the sitting-room window. In this way you could pay her a visit without anyone knowing about it. That is what you used to do, is it not?”

“How did you know?”

“Because you dropped a piece of paper inside Mrs. Underwood’s bedroom window on your return from one of these visits. I do not know whether you meant to drop it there or not. I think not. I think you had it in your hand, and that you dropped it as you were steadying yourself by the sash whilst passing the window. Now this piece of paper was the corner of a letter which Mrs. Underwood had written. The rest of the letter was found in Miss Roland’s bag. So, you see, it was quite clear to me that you must have passed Mrs. Underwood’s window on a return journey from Miss Roland’s flat. There was really no other way in which that particular piece of paper could have reached the spot where Mrs. Underwood found it. Her bedroom door and the door of the flat were both locked. There was no other way.”

Ivy stared. Then she moistened her lips with her tongue and said,

“That’s right.”

“How did the letter get torn?”

Miss Silver had hardly asked the question before she was aware of having made a mistake. Ivy’s immediate reaction was that after all Miss Silver didn’t know everything. Quite visibly she rallied to the defence of what she was determined to hide. Something uncommonly like impudence looked sideways out of the reddened eyes.

“Coo! Don’t you know?”

Miss Silver’s manner became gently repressive.

“I think you tried to snatch it.”

Impudence ran away in a fright. Ivy gaped.

“It wasn’t hers-she didn’t ought to have had it-I told her so. Mind you, it wasn’t a row. She only laughed, but I thought I was going to lose my temper, so I came away.”

“How did she get the letter?” said Miss Silver.

Sharp and quick, Ivy’s Cockney wit prompted her. “Here’s your chance. Take it, you fool!” Easy-easy-easy-She opened her eyes in a blank stare.

“How do I know how she got it? Same way we all do. Postman comes reg’lar, doesn’t he?”

“How did you know she had it?”

No way out after all. And your heart coming right up into your throat by the feel of it. What could you do?

She did the only thing that was any good. It happened also to be the easiest thing in the world. She gave a rending sob and burst into tears.

“What are you getting at? What’s it got to do with me? And what’s it got to do with you? I don’t know nothing about it, and I wish I was dead!” Upon which she ran out of the kitchen and banged the door.

Miss Silver, listening with an air of sober attention, heard the slam of the bedroom door and the sound of the key clicking round in the lock.

Miss Silver sighed, smiled resignedly, and went in search of Mrs. Underwood, whom she found in her bedroom, and apparently without occupation. She was sitting in a chintz-covered easy chair beside a small gas fire turned low. There was plenty of daylight outside, but it was of a cold and cheerless nature.

Miss Silver was pleased to observe the fire. She considered the fumed-oak mantelpiece and the surround of rose-coloured tiles very tasteful. Drawing a smaller chair up to the hearth, she sat down and came to the point.

“Ivy and Miss Roland were old friends. I was convinced that this must be so, and she made no attempt to deny it. She has been in the habit of walking along the ledge outside your window and climbing up the fire-escape to visit her friend.”

“That narrow ledge? Impossible!”

“For you or me, yes, but not for a girl who had been trained as an acrobat. I felt sure from the beginning that she was not walking in her sleep. Her possession of a piece torn from your letter to the person who was blackmailing you would have been too much of a coincidence. I was sure that there was some connection between her and the person who had your letter, but when you discovered that this person was Miss Roland, I was not altogether convinced that it was she who was the blackmailer. It seemed unlikely that she would in that case have been so careless as to carry your letter in her bag, and to allow you to catch sight of it there. When she was murdered, I felt tolerably sure that it was not she who was blackmailing you. It also became evident that the affair was extremely serious, and that the blackmailer was a dangerous person who would stick at nothing. You have not been entirely frank with me, but I now urge you in your own interest and from a sense of public duty to tell me what I want to know.”

“What is it?” Mabel Underwood was breathing quickly. Her eyes were fixed on Miss Silver’s face.

Miss Silver coughed.

“Pray do not be alarmed. Remember that I am trying to help you. I cannot do so while you keep me in ignorance. The matter is urgent. I want to know whether it was only money that was demanded of you.”

All the colour dropped away from the plump cheeks, leaving them pale under two rouged patches. A fumbling hand went up to the throat.