"Could he have come from this house?" French asked sternly.

"I guess, if he'd come out from the front door, he might just have done it," the man admitted.

Quest and the Inspector exchanged glances.

"He's done us!" Quest muttered,--"done us like a couple of greenhorns!"

The Inspector's rubicund countenance was white with fury. His head kept turning in the direction of Laura, to whom the Professor was busy rendering first aid.

"If I never take another job on as long as I live," he declared, "I'll have that fellow before I'm through!"

2.

The Professor roused himself from what had apparently been a very gloomy reverie.

"Well," he announced, "I must go home. It has been very kind of you, Mr.

Quest, to keep me here for so long."

Quest glanced at the clock.

"Don't hurry, Mr. Ashleigh," he said. "We may get some news at any moment.

French has a dozen men out on the search and he has promised to ring me up immediately he hears anything."

The Professor sighed.

"A man," he declared, "who for twenty years can deceive his master as utterly and completely as Craig has done me, who is capable of such diabolical outrages, and who, when capture stares him in the face, is capable of an escape such as he made to-day, is outside the laws of probability. Personally, I do not believe that I shall ever again see the face of my servant, any more than that you, Quest, will entirely solve the mystery of these murders and the theft of the Rheinholdt jewels."

Lenora, who, with her hat on, was packing a small bag at the other end of the room, glanced up for a moment.

[Ill.u.s.tration: QUEST IS MYSTIFIED AT FINDING THE JEWELS IN THE BLACK BOX, WHICH WAS ON THE FLOOR.]

[Ill.u.s.tration: "SURE AN' ME NAME'S NOT CRAIG--IT'S MARTY O'TOOLE, SIR."

THEY HAD FOOLED THE CRIMINOLOGIST.]

"The man is a demon!" she exclaimed. "He would have sacrificed us all, if he could. When I think of poor Laura lying there in the hospital, crushed almost to death, so that he could save his miserable carca.s.s, and realise that he is free, I feel--"

She stopped short. Quest looked at her and nodded.

"Don't mind hurting our feelings, Lenora," he said. "French and I are up against it all right. We're second best, at the present moment--I'll admit that--but the end hasn't come yet."

"I am sorry," she murmured. "I was led away for a moment. But, Mr. Quest,"

she went on piteously, "can't we do something? Laura's so brave. She tried to laugh when I left her, an hour ago, but I could see all the time that she was suffering agony. Fancy a man doing that to a woman! It makes me feel that I can't rest or sleep. I think that when I have left the hospital I shall just walk up and down the streets and watch and search."

Quest shook his head.

"That sort of thing won't do any good," he declared. "It isn't any use, Lenora, working without a plan. That's why I'm here now, waiting. I want to formulate a plan first."

"Who are we," the Professor asked drearily, "to make plans against a fiend like that? What can we do against men who have revolving staircases and trolley-loads of river pirates waiting for them? You may be a scientific criminologist, Quest, but that fellow Craig is a scientific criminal, if ever there was one."

Quest crossed the room towards his cigar cabinet, and opened it. His little start was apparent to both of them. Lenora laid down the bag which she had just lifted up. The Professor leaned forward in his chair.

"What is it, Quest?" he demanded.

Quest stretched out his hand and picked up from the top of the cigars a small black box! He laid it on the table.

"Unless I am very much mistaken," he said, "it is another communication from our mysterious friend."

"Impossible!" the Professor exclaimed hoa.r.s.ely.

"How can he have been here?" Lenora cried.

Quest removed the lid from the box and drew out a circular card. Around the outside edge was a very clever pen and ink sketch of a lifebuoy, and inside the margin were several sentences of clear handwriting. In the middle was the signature--the clenched hands! Quest read the message aloud--

"In the great scheme of things, the Supreme Ruler of the Universe divided an inheritance amongst His children. To one He gave power, to another strength, to another beauty, but to His favourites He gave cunning."

They all looked at one another.

"What does it mean?" Lenora gasped.

"A lifebuoy!" the Professor murmured.

They both stared at Quest, who remained silent, chewing hard at the end of his cigar.

"Every message," he said, speaking half to himself, "has had some significance. What does this mean--a lifebuoy?"

He was silent for a moment. Then he turned suddenly to the Professor.

"What did you call those men in the motor-truck, Professor--river pirates?

And a lifebuoy! Wait."

He crossed the room towards his desk and returned with a list in his hand.

He ran his finger down it, stopped and glanced at the date.

"The _Durham_," he muttered, "cargo cotton, destination Southampton, sails at high tide on the 16th. Lenora, is that calendar right?"

"It's the 16th, Mr. Quest," she answered.

Quest crossed the room to the telephone.

"I want Number One Central, Exchange," he said. "Thank you! Put me through to Mr. French's office.... Hullo, French! I've got an idea. Can you come round here at once and bring an automobile? I want to get down to the docks--not where the pa.s.senger steamers start from--lower down.... Good!

We'll wait."

Quest hung up the receiver.

"See here, Professor," he continued, "that fellow wouldn't dare to send this message if he wasn't pretty sure of getting off. He's made all his plans beforehand, but it's my belief we shall just get our hands upon him, after all. Lenora, you'd better get along round to the hospital. You don't come in this time. It's bad enough to have Laura laid up--can't risk you.

There'll be a little trouble, too, before we're through, I'm afraid."

Lenora sighed as she picked up her bag.