“Doctor—­did you get it?” she repeated, drawing the Doctor aside.

The Doctor gave her a look of apparent bewilderment.

“My dear child,” he said softly, “are you sure that you put it there?”

Dale felt as if she had received a blow in the face.

“Why, yes—­I—­” she began in tones of utter dismay.  Then she stopped.  The Doctor’s seeming bewilderment was too pat—­too plausible.  Of course she was sure—­and, though possible, it seemed extremely unlikely that anyone else could have discovered the hiding-place of the blue-print in the few moments that had elapsed between the time when Billy took the tray from the room and the time when the Doctor ostensibly went to find it.  A cold wave of distrust swept over her—­she turned away from the Doctor silently.

Meanwhile Anderson had entered, slamming the terrace-door behind him.

“I couldn’t find anybody!” he said in an irritated voice.  “I think that Jap’s crazy.”

The Doctor began to struggle into his topcoat, avoiding any look at Dale.

“Well,” he said, “I believe I’ve fulfilled all the legal requirements —­I think I must be going.”  He turned toward the door but the detective halted him.

“Doctor,” he said, “did you ever hear Courtleigh Fleming mention a Hidden Room in this house?”

If the Doctor started, the movement passed apparently unnoted by Anderson.  And his reply was coolly made.

“No—­and I knew him rather well.”

“You don’t think then,” persisted the detective, “that such a room and the money in it could be the motive for this crime?”

The Doctor’s voice grew a little curt.

“I don’t believe Courtleigh Fleming robbed his own bank, if that’s what you mean,” he said with nicely calculated emphasis, real or feigned.  He crossed over to get his bag and spoke to Miss Cornelia.

“Well, Miss Van Gorder,” he said, picking up the bag by its blackened handle, “I can’t wish you a comfortable night but I can wish you a quiet one.”

Miss Cornelia watched him silently.  As he turned to go, she spoke.

“We’re all of us a little upset, naturally,” she confessed.  “Perhaps you could write a prescription—­a sleeping-powder or a bromide of some sort.”

“Why, certainly,” agreed the Doctor at once.  He turned back.  Miss Cornelia seemed pleased.

“I hoped you would,” she said with a little tremble in her voice such as might easily occur in the voice of a nervous old lady.  “Oh, yes, here’s paper and a pencil,” as the Doctor fumbled in a pocket.

The Doctor took the sheet of paper she proffered and, using the side of his bag as a pad, began to write out the prescription.

“I don’t generally advise these drugs,” he said, looking up for a moment.  “Still—­”

He paused.  “What time is it?”

Miss Cornelia glanced at the clock.  “Half-past eleven.”