Besides, it is
more natural for a man to be driven insane by another's act than by his
own."

"Yes, if he loved the victim."

"And did not Bartow?"

"He does not mourn Mr. Adams."

"But he is no longer master of his emotions."

"Very true; but if we take any of his actions as a clew to the
situation, we must take all. We believe from his gestures that he is
giving us a literal copy of acts he has seen performed. Then, why pass
over the gleam of infernal joy that lights his face after the whole is
over? It is as if he rejoiced over the deed, or at least found
immeasurable satisfaction in it."

"Perhaps it is still a copy of what he saw; the murderer may have
rejoiced. But no, there was no joy in the face of the young man I saw
rushing away from this scene of violence. Quite the contrary. Mr. Gryce,
we are in deep waters. I feel myself wellnigh submerged by them."

"Hold up your head, madam. Every flood has its ebb. If you allow
yourself to go under, what will become of me?"

"You are disposed to humor, Mr. Gryce. It is a good sign. You are never
humorous when perplexed. Somewhere you must see daylight."

"Let us proceed with our argument. Illumination frequently comes from
the most unexpected quarter."

"Very well, then, let us put the old man's joy down as one of the
mysteries to be explained later. Have you thought of him as a possible
accomplice?"

"Certainly; but this supposition is open to the same objection as that
which made him the motive power in this murder. One is not driven insane
by an expected horror. It takes shock to unsettle the brain. He was not
looking for the death of his master."

"True. We may consider that matter as settled. Bartow was an innocent
witness of this crime, and, having nothing to fear, may be trusted to
reproduce in his pantomimic action its exact features."

"Very good. Continue, madam. Nothing but profit is likely to follow an
argument presented by Miss Butterworth."

The old detective's tone was serious, his manner perfect; but Miss
Butterworth, ever on the look-out for sarcasm from his lips, bridled a
little, though in no other way did she show her displeasure.

"Let us, then, recall his precise gestures, remembering that he must
have surprised the assailant from the study doorway, and so have seen
the assault from over his master's shoulder."

"In other words, directly in front of him. Now what was his first move?"

"His first move, as now seen, is to raise