"I think you girls have had as much as is good for you of this sort of business," he declared grimly.

"But it's all over now," Lenora protested.

Quest b.u.t.toned up his coat and motioned to French to follow him.

"I'm not so sure," he said. "I'll 'phone if we want you, Lenora. We shall be at the Professor's."

The two men drove to the outskirts of the city almost in silence, while several of the officers followed in another taxi. The Professor's house seemed more than ever deserted as they drew up at the front door. They entered without ringing and crossed the hall towards the library. On the threshold Quest paused and held up his finger.

"Some one is in there," he whispered, stepping quickly forward. "Come!"

He threw open the door. The room was empty, yet both Quest and French were conscious of a curious conviction that it had been occupied within the last few seconds. French even shook out the curtains and swung open the doors of a bureau. There was no sign of anybody, however, nor any evidence as to how they could have left the room.

"Queer, but it seemed to me I heard some one," French muttered.

"I was sure of it," Quest replied, shaking the curtains at the back of the door.

They stood still for a moment and listened. The silence in the empty house was almost unnatural. Quest turned away with a shrug of the shoulders.

"At any rate," he said, "Craig's dying thoughts must have been truthful.

Come."

He led the way to the fireplace, went down on his knees and pa.s.sed his hands over the bricks. The third one he touched, shook. He tapped it--without a doubt it was hollow. With his penknife he loosened the mortar a little and drew it out easily. The back was open. Inside was the black box.

"Craig's secret at last!" French muttered hoa.r.s.ely. "Bring it to the light, quick!"

They were unemotional men but the moment was supreme. The key to the mystery of these tragical weeks was there in their hands! Their eyes almost devoured those few hastily scrawled words buried with so much care:

_See page 62, January number, American Medical Journal 1905._

They looked at one another. They repeated vaguely this most commonplace of messages. As the final result of their strenuous enterprise, these cryptic words seemed pitifully inadequate. Quest's face darkened. He crumpled the paper in his fingers.

"There must be some meaning in this," he muttered. "It can't be altogether a fool's game we're on. Wait."

He moved towards a table which usually stood against the wall, but which had obviously been dragged out recently into the middle of the room. It was covered with bound volumes. Quest glanced at one and exclaimed softly.

"_American Medical Journal, 1905!_ French, there's something in this message, after all."

He turned over the pages rapidly. Then he came to a stop. Page 60 was there; page 62 had been neatly removed with a pair of scissors.

"The Professor!" he cried. "The Professor's been at work here!"

The two men stood looking at one another across the table. Strange thoughts were framing themselves in the brains of both of them. Then there came a startling and in its way a dramatic interlude. Through the empty house came the ringing of the electric bell from the front door, shrill and insistent. Without a moment's hesitation, Quest hurried out, and French followed him. On the door-step was another surprise. Lenora and Laura were there, the former carrying a small, black-bound volume.

"Don't be cross," she begged quickly. "We just had to come. Look! We picked this up underneath the chair where Craig was sitting. It must have slipped from his pocket. You see what is written on it? DIARY OF JOHN CRAIG."

Quest took it in his hand.

"This ought to be interesting," he remarked. "Come along in."

They pa.s.sed into the library. French lingered behind for a moment and caught up with them just as they were opening the book underneath the electric lamp.

"See what I've found!" he exclaimed. "It was just by the side of the wall there. Where's that journal?"

He spread out the piece of paper--it fitted exactly into the empty s.p.a.ce.

They all read together:

"Professor Ashleigh, after being bitten by the anthropoid, rapidly developed hydrophobia of a serious nature. After treatment with a new serum the patient was relieved of the hydrophobic symptoms, but to my horror this mild-mannered, humane man seems possessed at times of all the characteristics of the brutal anthropoid--cunning, thievery, brutality. I do not know what may come of this. I hesitate to put even these words on to paper. I am doubtful as to what course, in the interests of humanity, I ought to take.

(Signed) "JAMES MERRILL, M.D.

"Editor's Note. Just as we go to press, a cable announces the terrible death of Doctor Merrill, the writer of the above notes.

He was attacked by wild animals while alone in a South American jungle, and torn to pieces."

There was a queer little silence among the company. No one seemed inclined for speech. They looked at one another in dumb, wondering horror. Then Quest drew a penknife from his pocket and with a turn of his wrist forced the lock of the diary. They all watched him with fascinated eyes. It was something to escape from their thoughts. They leaned over as he spread the book out before him. Those first two sentences were almost in the light of a dedication:

"For ten years I have protected my master, Professor Edgar Ashleigh, at the cost of my peace of mind, my happiness, my reputation. This book, even though it be too late to help me, shall clear my reputation."

Quest closed the volume.

"French," he decided, "we must find the Professor. Will you have your men search the house and grounds immediately?"

The Inspector left the room like a dazed man. They could hear him giving orders outside.

"The next page," Lenora begged. "Just one page more!"

Quest hesitated for a moment. Then he turned it over. All three read again:

"Ten years of horror, struggling all the while to keep him from that other self, that thing of b.e.s.t.i.a.lity, to keep his horrible secret from the world, to cover up his crimes, even though their shadow should rest upon me. Now Sanford Quest has come. Will this mean discovery?"

"Another page," Lenora faltered.

"No more," Quest said. "Don't you see where it is leading us? We have the truth here. Wait!"

He strode hastily to the door. French and one of the plain-clothes men were descending the stairs.

"Well?" Quest asked breathlessly.

"The Professor is not in the house," French reported. "We are going to search the grounds."

Quest returned to the library. Lenora clung to his arm. The diary lay still upon the table.

Quest opened the volume slowly. Again they all read together:

"The evil nature is growing stronger every day. He is developing a sort of ferocious cunning to help him in his crimes. He wanders about in the dark, wearing a black velvet suit with holes for his eyes, and leaving only his hands exposed. I have watched him come into a half-darkened room and one can see nothing but the hands and the eyes; sometimes if he closes his eyes, only the hands."

"Mrs. Rheinholdt!" Quest muttered. "Wait. I know where that suit is."

He hastened to a cupboard at the farther end of the room, s.n.a.t.c.hed some garments from it and vanished into the hall.