“No, no, no,” Blackburn grimaced.  “I wasn’t cold.  I couldn’t have been.”

“There’s no question,” Bobby said hoarsely.

“No question,” Robinson repeated.

Katherine shrank from her uncle as he had shrunk from her in the library the night of the murder.

“What do you make of it?” the district attorney asked Rawlins.

The detective, who had remained crouched at the side of the grave, arose, brushing the dirt from his hands, shaking his head.

“What is one to make of it, sir?”

Paredes spoke softly to Graham.

“The Cedars wants to be left alone to the dead.  We would all be better away from it.”

“You won’t go yet awhile,” Robinson said gruffly.  “Don’t forget you’re still under bond.”

The detail no longer seemed of importance to Bobby.  The mystery, centreing in the empty grave, was apparently inexplicable.  He experienced a great pity for his grandfather; and, recalling that strengthening moment with Katherine, he made up his mind that there was only one course for him.  It might be dangerous in itself, yet, on the other hand, he couldn’t go to Katherine while his share in the mystery of the Cedars remained so darkly shadowed.  He had no right to withhold anything, and he wouldn’t ask Graham’s advice.  He had stepped all at once into the mastery of his own destiny.  He would tell Robinson, therefore, everything he knew, from the party with Maria and Paredes in New York, through his unconscious wanderings around the house on the night of the first murder, to the moment when Graham had stopped his somnambulistic excursion down the stairs.

Robinson turned his light away from the grave.

“There’s nothing more to do here.  Let us go back.”

The little party straggled through the snow to the house.  The hall fire smouldered as pleasantly as it had done before they had set forth, yet an interminable period seemed to have elapsed.  Silas Blackburn went close to the fire.  He sank in a chair, trembling.

“I’m so cold,” he whined.  “I’ve never been so cold.  What is the matter with me?  For God’s sake tell me what is the matter!  Katherine—­if—­if nothing happens, we’ll close the Cedars.  We’ll go to the city where there are lots of lights.”

“If you’d only listened to Bobby and me and gone long ago,” she said.

Robinson stared at the fire.

“I’m about beaten,” he muttered wearily.

Rawlins, with an air of stealth, walked upstairs.  Graham, after a moment’s hesitation, followed him.  Bobby wondered why they went.  He caught Robinson’s eye.  He indicated he would like to speak to him in the library.  As he left the hall he saw Paredes, who had not removed his hat or coat, start for the front door.

“Where are you going?” he heard Robinson demand.

Paredes’s reply came glibly.

“Only to walk up and down in the court.  The house oppresses me more than ever to-night.  I feel with Mr. Blackburn that it is no place to stay.”