When Hilda carried it out he followed her.

“See here,” he said. “What’s been going on? What’s this about Ida being missing?”

“I don’t know that she is, doctor.”

“Well, what’s the row about? Maggie says you’ve practically torn up the old lady’s room.”

“We’ve been trying to locate the combination of her safe.”

He whistled and looked back at Jan’s door.

“I wouldn’t tell her that, Miss Adams,” he said. “It might upset her.”

He declined to elaborate, and Hilda had that to puzzle over during the evening, as well as Ida’s continued absence. At eight o’clock William had sent a wire to her people in the country, and he and Maggie were waiting in the kitchen for an answer. Young Brooke, having eaten his dinner, left for his office hours and came back at nine. Marian went to bed, and Carlton and Susie were in the library. Hilda, not needed anywhere, sat in her room and watched the twilight turn into night. She had gathered up a lot of odds and ends, but where did they take her? She was no nearer the solution of the crime than she had been before.

Ida? What about Ida? She could have discovered the opening into Mrs. Fairbanks’s room; the panel not entirely closed, and Ida on her knees, washing the floor of the closet. She could even have slipped the bats into the room. She had been a country girl. She would not be afraid of such things. But why? What would be her motive?

She went back to the morning of the murder; Ida in her room by the window, her hands folded in her lap and a queer look on her long thin face as she and the inspector entered. She had been afraid, so afraid that she tried to rise and could not. And now she was missing.

In the next room the young people were talking. Hilda got up and moving carefully went to the front hall. Above her the third floor loomed dark and empty, and the long passage to Ida’s room was ghostly. As the evening cooled the old house creaked, and Hilda, remembering the figure she had seen at the top of the stairs, felt small goose pimples on her flesh.

Once back in the girl’s room, however, she felt better. She turned on the light and looked about her. There was no indication that she had intended to leave. A pair of washed stockings hung over the back of a chair, a discarded blue uniform lay on the bed, and a battered suitcase stood on the closet floor.

The wastebasket was empty, except for a newspaper, but under the pine dresser she found a scrap of paper. It was part of a letter, and it contained only two words. On one line was the word “sorry” and below it “harmless.” Nowhere could she find any other bits, and at last she gave it up and put out the light.

She went quietly forward and down to the second floor. To her surprise the door into Mrs. Fairbanks’s room was open, and she stepped inside. Young Brooke was there. He had opened the drawer of the table and had taken something out.