“Yes.”

“And then—­then, when you left Mr. Embury’s room—­when you left him for the night-did you close his door?”

“I did.”

“And that, of itself, locked that door?”

“Yes, I suppose so.”

“Stop saying you suppose so.  You know it did!  You’ve lived in this house two years; you know how those doors work—­you know your closing that door locked it?  Didn’t it?”

“Yes, it did.  I turned the knob afterward to make sure.  I always do that.”

Ferdinand now seemed to be as discursive as he was reticent before.  “And I know Miss Eunice’s—­Mrs, Embury’s door was locked, because she had to unbolt it before I could get in this morning.”

“But look here,” Driscoll broke in, “are these doors on that snap-bolt all day?  Isn’t that rather an inconvenience?”

“Not all day,” vouchsafed Ferdinand.  “They can be turned so the bolt doesn’t catch, and are turned that way in the daytime, usually.”

“But,” and Driscoll looked at him intently, “you can swear that the bolts were on last night?”

“Yes, sir—­”

“You can’t!” Hendricks shot at him.  The lawyer had been listening in silence, but he now refuted Ferdinand.  “You don’t know that Mrs, Embury put on the catch of her door when she closed it.”

“I do, sir; I heard it click.”

“You are very observant,” said Shane; “peculiarly so, it seems to me.”

“No, sir,” and Ferdinand looked thoughtful; “but, you see, it’s this way.  Every night I hear the click of those locks, and it sort of seems natural to me to listen for it.  If it should be forgotten, I’d think it my duty to call attention to it.”

“A most careful butler, on my word!” Shane’s tone was a little sneering.

“He is, indeed!” Eunice defended; “and I can assert that it is because of his faithfulness and efficiency that we have always felt safe at night from intrusion by marauders.”

“And you did lock your door securely last night, Mrs, Embury?”

“I most assuredly did!  I do every night.  But that does not prove that I killed my husband.  Nor that Miss Ames did.”

“Then your theory—­”

“I have no theory.  Mr. Embury was killed—­it is for you detectives to find out how.  But do not dare to say—­or imply —­that it was by the hand of his wife—­or his relative!”

She glanced fondly at Miss Ames, and then again assumed her look of angry defiance toward the two men who were accusing her.

“It is for you to find out how,” said Mason Elliott, gravely.  “It is incredible that Mrs, Embury is the guilty one, though I admit the incriminating appearance of the henbane.  But I’ve beet thinking it over, and while Mr. Driscoll’s surmise that the deed can possibly be traced to one who recently saw the play of ‘Hamlet,’ yet he must remember that thousands of people saw that play, and that therefore it cannot point exclusively toward Mrs, Embury.”