With a graver fear the detective glanced at the door of the hall.

McDonald had dragged himself that far. He raised his trembling hand, stretching it towards the bed in a gesture, it seemed to Garth, of impossible accusation. Then the crouched figure toppled and fell across the threshold while from somewheres beyond the door a high girlish laugh rippled.

Garth sprang forward and knelt by the old man, reluctant to search for what he expected to find. There it was at the back of the coat, a jagged tear whose edges were stained, showing where the knife had penetrated the shoulder. The wound didn't look deep or dangerous, and in his unconsciousness McDonald breathed regularly. So Garth hurried back to the bed and examined the knife. There was no ambiguity about the red stains on the blade. The knife, resting close to the dead hand, had wounded McDonald who had seemed to accuse the still form whose note projected the impression of having been written after death.

Garth smothered his morbid thoughts. McDonald's daughter was the living force, probably at large in this house, that he wanted to chain. If she were guilty of the earlier crime she had sufficient motive for this attempt to keep the old man silent. She could have got such a knife from the kitchen. So, for that matter, could Clara. But the eccentric had laughed. Was that merely coincidence? Garth ran across the hall and listened at her door with an increasing excitement. He heard the running of water, regularly interrupted, as if by hands being cleansed under an open faucet. He tried the door and found it unlocked. He entered, staring at the daring indifference of the old woman who stepped from the bath room, calmly drying her hands on a towel.

"Come in, policeman," she said in her high girlish voice. "Don't suffer in the black hall."

"Let me have that towel," he cried.

Without hesitation she offered him the piece of linen. It showed no stains, nor were there stains to be found about the wash basin, but the slab of marble in which it was set was damp as if it had just now been carefully cleansed. She watched, her wrinkled face set in an expression of contempt.

"What are you up to? Think if I wanted to do anything wrong I'd let you find me out?"

"Then you know," he said, "what happened out there in the hall. I heard you laugh."

She started. Her voice was lower. At last it was as old as herself.

"Things always happen out there. It is crowded with the people who have lived in this house before us--unhappy and angry people. Often I have seen and heard the black thing out there. I would never laugh at her."

Again the doubt of her senility attacked him.

"You can't impress me with that," he said harshly. "I am talking about McDonald. He was stabbed out there a few minutes ago."

She laughed foolishly.

"Horrid old man! But why should I want to see him stabbed?"

He watched her closely.

"I saw you strike him. You didn't have enough strength to send the blow home."

The a.s.surance of her voice increased his doubt. Whatever her mental state she was at least purposeful.

"You need gla.s.ses, policeman. Don't neglect your eyes. You have only one pair."

He felt himself against a blank wall, and there was McDonald to think of. He asked one more question.

"When did you last see McDonald's daughter?"

"Maybe at dinner last night," she said. "Nice girl, in spite of her father. I must go back to my knitting, policeman."

Garth left her, hurrying down stairs to the front door. He called the policeman from the shadows of the portico, instructing him to go to the large apartment house on the corner where he would almost certainly find a physician.

As he gave his directions he saw Nora's slender figure cross the street and come up the steps, and, as he looked at the pretty Latin face, expressive of an exceptional intelligence, his morose and puzzled mind brightened. He was surprised to see her now, and a little worried, for a grave menace existed for every one in this house. Moreover, the case mystified him to the point where he felt he must find the solution himself. He didn't care to place himself again under obligations to her.

Rather he was ambitious to impress her, perhaps to the removal of her reserve.

"Father's told me about the case," she said. "I couldn't keep away, because you're so hard-headed, Jim."

Smiling whimsically, she glanced at his frayed watch ribbon.

"I see you haven't found the answer yet. Tell me everything you have learned while you have been torturing that poor ribbon."

"Ghosts or not, Nora," he answered, "the house isn't healthy, and I'd rather you didn't stay."

She laughed and walked in. Shrugging his shoulders, he followed her, closed the door, and told her what had happened since he had telephoned the inspector. Her face, he noticed, had grown pale, and a troubled look had entered her eyes. She shivered.

"What an uncomfortable place! I can guess what Clara meant. Don't you get an impression of great suffering, Jim?"

He was familiar with her superst.i.tious sensibility which at times seemed nearly psychic. It irritated him that to his own matter-of-fact mind the house had from the first conveyed a sense of unhealth. As he started to laugh at her, Nora with a quick movement shrank against the wall.

"What's that?" she whispered.

Garth strained forward, listening, too. He had heard what Clara had described, a crying, smothered and scarcely audible, and he knew what the girl had meant when she had spoken of a voice from the grave--a dead voice.

Across the moaning cut a shrill feminine scream.

"Stay here," Garth called to Nora as he started up the stairs.

He heard her voice, like an echo behind him, as full of misgivings as Clara's had been.

"I am afraid."

At the foot of the attic stairs he saw the white figure of Mrs. Taylor, staring upward, trembling, hysterical, a violent fear in her eyes.

"You heard it, too," she breathed. "It wasn't the wind."

With a shuddering gesture she indicated McDonald's still form.

"He isn't dead," Garth said.

While she relaxed a little the fear in her eyes didn't diminish.

"I--I heard her moan," she said. "I opened my door, and there she was--a black thing--bending over him like--like a vampire. I couldn't seem to see her face. She ran up these stairs, and I could see through the banisters that she went in the big attic room--the room they always talked about where the woman--"

She broke off, screaming sharply again.

"Look out! Back of you! There's something black creeping up the stairs--"

CHAPTER XVIII

THE STAINED ROBE

Garth had been aware of Nora's slow ascent. As he turned she reached the upper floor and the light from the well caught her face.