They heard Paredes and Doctor Groom on the stairs.

"What's this?" the doctor rumbled as he came up.

"I--I'm sorry I forgot myself," Katherine said through her chattering
teeth. She turned to Robinson. "I am going to my room. You needn't be
afraid. I shan't leave it until you come to take me."

"Truly I hope it won't be necessary," the district attorney answered.

She hurried away. Rawlins grinned at Paredes.

"I'm wondering what the devil you know."

Robinson made no secret of what had happened. In reply to the questions
of Paredes and the doctor he told of the discovery of the evidence and of
the stout hat-pin that had, unquestionably, caused death. The man made it
clear enough, however, that he didn't care to have Paredes know of
Bobby's plan to spend the night in the old room, and Rawlins, Bobby, and
Graham indicated that they understood.

"It's quite absurd that any one should think Katherine guilty," the
doctor said to Robinson. "This evidence and its presence in her room are
details that don't approach the heart of the mystery. That's to be found
only in the old room, and I don't think any one wants to tempt it again.
In fact, I'm not sure one can learn the truth there and live. You know
what happened to Howells when he tried. Silas Blackburn went there, and
none of us can understand the change that's taken place. I have been
watching him closely. So has Mr. Paredes. We have seen him become grayer.
We have seen his eyes alter. He sits shaking in his chair. Since we came
back from the grave the man--if we can call him a man--seems to
have--shrunk."

"Yes," Paredes said. "Perhaps we shouldn't have left him alone. Let us go
back. Let us see if he is all right."

Rawlins laughed skeptically.

"You're not afraid he'll melt away!"

"I'm not so sure he won't," Paredes answered.

They followed him downstairs. Because of the position of Blackburn's
chair they could be sure of nothing until they had reached the lower
floor and approached the fireplace. Then they saw. It was as if Paredes's
far-fetched fear had been realized. Blackburn was not in his chair, nor
was he to be found in the hall. Even then, with the exception of Paredes,
they wouldn't take the thing seriously. Since the old man wasn't in the
hall; since he couldn't have gone upstairs, unobserved by them, he must
be either in the library, the dining room, or the rear part of the house.
There was no one in the library or the dining room; and Jenkin