Silas Blackburn’s great grandfather, he told the detective, had been carried to that bed from a Revolutionary skirmish with a bullet at the base of his brain.  For many hours he had raved deliriously, fighting unsuccessfully against the final silence.

“It has been a legend in the family, as these young people will tell you, that Blackburns die hard, and there are those who believe that people who die hard leave something behind them—­something that clings to the physical surroundings of their suffering.  If it was only that one case!  But it goes on and on.  Silas Blackburn’s father, for instance, killed himself here.  He had lost his money in silly speculations.  He stood where you stand, detective, and blew his brains out.  He fell over and lay where his son lies, his head on that pillow.  Silas Blackburn was a money grubber.  He started with nothing but this property, and he made a fortune, but even he had enough imagination to lock this room up after one more death of that kind.  It was this girl’s father.  You were too young, Katherine, to remember it, but I took care of him.  I saw it.  He was carried here after he had been struck at the back of the head in a polo match.  He died, too, fighting hard.  God!  How the man suffered.  He loosened his bandages toward the end.  When I got here the pillow was redder than it is to-day.  It strikes me as curious that the first time the room has been slept in since then it should harbour a death behind locked doors—­from a wound in the head.”

Paredes’s fingers were restless, as if he missed his customary cigarette.  The detective strolled to the window.

“Very interesting,” he said.  “Extremely interesting for old women and young children.  You may classify yourself, doctor.”

“Thanks,” the doctor rumbled.  “I’ll wait until you’ve told me how these doors were entered, how that wound was made, how this body turned on its side in an empty room.”

The detective glanced at Bobby.  His voice lacked confidence.

“I’ll do my best.  I’ll even try to tell you why the murderer came back this afternoon to disturb his victim.”

Bobby went, curiously convinced that the doctor had had the better of the argument.

For a moment Katherine, Graham, Paredes, and he were alone in the main hall.

“God knows what it was,” Graham said, “but it may mean something to you, Bobby.  Tell us carefully, Katherine, about the sounds that came to you across the court.”

“It was just what I heard last night when he died,” she answered.  “It was like something falling softly, then a long-drawn sigh.  I tried to pay no attention.  I fought it.  I didn’t call at first.  But I couldn’t keep quiet.  I knew we had to go to that room.  It never occurred to me that the detective or the coroner might be there moving around.”

“You were alone up here?” Graham said.

“I think so.”

“No,” Bobby said.  “I was in my room.”