"I'm stopping at the Johnsons' on my way--one of their children is ill--or supposed to be." He took a step toward the door, then he turned toward Dale again.
"Take a parting word of advice," he said.

"The thing to do with a midnight prowler is--let him alone.

Lock your bedroom doors and don't let anything bring you out till morning." He glanced at Dale to see how she took the advice, his hand on the knob of the door.
"Thank you," said Dale seriously.

"Good night, Doctor--Billy will let you out, he has the key." "By Jove!" laughed the Doctor, "you are careful, aren't you! The place is like a fortress! Well--good night, Miss Dale--" "Good night." The door closed behind him--Dale was left alone.
Suddenly her composure left her, the fixed smile died.

She stood gazing ahead at nothing, her face a mask of terror and apprehension.
But it was like a curtain that had lifted for a moment on some secret tragedy and then fallen again.