That night at dinner time a stranger appeared at the captain's table. A dark, thick-browed man, in morning clothes of professional cut, was shown by one of the saloon stewards to a seat which had hitherto been vacant. Crawshay, whose place was nearly opposite, leaned across at once with an air of interest.

"Good evening, Doctor," he said.

"Good evening, sir," was the somewhat gruff reply.

"Glad to see that you are able to come in and join us," Crawshay continued, unabashed. "You are, I believe, the physician in attendance on Mr. Phillips. I am very interested in illnesses. As a matter of fact, I am a great invalid myself."

The doctor contented himself with a muttered monosyllable which was not brimful of sympathy.

"This is a very remarkable expedition of yours," Crawshay went on. "I am a man of very little sentiment myself—one place to me is very much like another—so I do not understand this wild desire on the part of an invalid to risk his life by undertaking such a journey. It is a great feat, however. It shows what can be accomplished by a man of determination, even when he is on the point of death." "Who said that my patient was on the point of death?" the doctor demanded brusquely.

"It is common report," Crawshay assured him. "Besides, as you know, the New York press got hold of the story before you started, and the facts were in all the evening papers."

"What facts?"

"Didn't you read them? Most interesting!" Crawshay continued. "They all took the same line, and agreed that it was an absolutely unprecedented occurrence for a man to embark upon an ocean voyage only a few days after an operation for appendicitis, with double pneumonia behind, and angina pectoris intervening. Almost as unusual," Crawshay concluded with a little bow, "as the fact of his being escorted by the most distinguished amateur nurse in the world, and a physician of such distinction as Doctor—Doctor—Dear me, how extraordinary! For the moment I must confess that your name has escaped me."

The heavy-browed man leaned forward a little deliberately towards his vis-À-vis. His was not an attractive personality. His features were large and of bulldog type. His forehead was low, and his eyes, which gave one the impression of being clear and penetrating, were concealed by heavy spectacles. His hands only, which were well-shaped and cared for, might have indicated his profession.

"My name," he said, "is Gant—Doctor James H. Gant. You are not, I presume, a medical man yourself?"

Crawshay shook his head.

"A most admirable profession," he declared, "but one which I should never have the nerve to follow."

"You do not, therefore, appreciate the fact," Doctor Gant continued, "that a medical man, especially one connected with a hospital of such high standing as St. Agnes's, does not discuss his patient's ailments with strangers."

"No offence, Doctor—no offence," Crawshay protested across the table. "Mine is just the natural interest in a fellow sufferer of a man who has known most of the ailments to which we weak humans are subject."

"I suppose, as we have the pleasure of your company this evening," the captain intervened, "Miss Beverley will be an absentee?"

"Miss Beverley at the present moment is taking my place," the doctor replied. "She insisted upon it. Personally, I am used to eating at all times and in all manner of places."

There was a brief silence, during which Crawshay discussed the subject of inoculation for colds in the head with his neighbour on the other side, and the doctor showed a very formidable capacity for making up for any meals which he might have missed by too rigid an attention to his patient. The captain presently addressed him again.

"Have you met our ship's doctor yet?" he enquired.

"I have had that honour," Doctor Gant acknowledged. "He was good enough to call upon me yesterday and offer his assistance should I require it."

"A very clever fellow, I believe," the captain observed.

"He impressed me some," the other confessed. "If any further complications should arise, it will be a relief for me to consult him."

The subject of the sick man dropped. Crawshay walked out of the saloon with the captain and left him at the bottom of the stairs.

"I'll take the liberty of paying you a short call presently, Captain, if I may," he said. "I just want to fetch my wraps. And by-the-by, did I tell you that I have been fortunate enough to find a pair of rubbers that just fit me, at the barber's? One of the greatest blessings on board ship, Captain, believe me, is the barber's shop. It's like a bijou Harrod's or Whiteley's—anything you want, from an elephant to a needle, you know. In about ten minutes, Captain, if I shan't be disturbing you."

The captain found the purser on deck and took him into his cabin.

"I saw you speaking to Doctor Gant in the gangway," the former observed. "I wonder what he really thinks about his patient?"

"I think I can tell you that, sir, without betraying any confidences," the purser replied. "Unless a miracle happens, there'll be a burial before we get across. Poor fellow, it seems too bad after such an effort."

The captain nodded sympathetically.

"After all, I can understand this hankering of a man to die in his own country," he said. "I had a brother once the same way. They brought him home from Australia, dying all the way, as they believed, but directly he set foot in England he seemed to take on a new lease of life—lived for years afterwards." "Is that so?" the purser remarked. "Well, this fellow ought to have a chance. It's a short voyage, and he has his own doctor and nurse to look after him."

"Let's hope they'll keep him alive, then. I hate the burial service at sea."

The captain turned aside and filled his pipe thoughtfully.

"Dix," he continued, "as you know, I am not a superstitious man, but there seems to be something about this trip I can't fathom."

"Meaning, sir?"

"Well, there's this wireless business, first of all. We shall close it up in about thirty-six hours, you know, and in the meantime I have been expecting half a dozen messages, not one of which has come through."

"Young fellow of the highest character, Robins," the purser remarked drily.

"That may be," the captain agreed, "and yet I can't get rid of my premonition. I wouldn't mind laying you anything you like, Dix, that we don't sight a submarine, and shouldn't, even if we hadn't our guns trained."

"That's one comfort, anyway. Being a family man, sir—"

"Yes, I know all about your family, Dix," the captain interrupted irritably, "but just at the present moment I am more interested in what is going on in my ship. I begin to believe that Mr. Crawshay's voyage through the air wasn't altogether a piece of bravado, after all."

The purser smiled a little incredulously. "He sent round this evening to know if I could lend him some flannel pyjamas," he said,—"says all the things that have been collected together for him are too thin. That man makes me tired, sir."

"He makes me wonder."

"How's that, sir?"

"Because I can't size him up," the captain declared. "There isn't a soul on board who isn't laughing at him and saying what a sissy he is. They say he has smuggled an extra lifebelt into his cabin, and spends half his time being seasick and the other half looking out for submarines."

"That's the sort of fellow he seems to me, anyway," the purser observed.

"I can't say that I've quite made up my mind," the captain pronounced.
"I suppose you know, Dix, that he was connected with the Secret
Service at the English Embassy?"

"I didn't know it," Dix replied, "but if he has been, Lord help us! No wonder the Germans have got ahead of us every time!"

"I don't think he was much of a success," the other continued, "and as a matter of fact he is on his way back to England now to do his bit of soldiering. All the same, Dix, he gave me a turn the other day."

"How's that, sir?"

"Showed me an order, signed by a person I won't name," the captain went on, lowering his voice, "requesting me to practically run the ship according to his directions—making him a kind of Almighty boss."

Mr. Dix opened his lips and closed them again. His eyes were wide open with astonishment. There was an indecisive knock at the door, which at a gesture from the captain he opened. Wrapped in a huge overcoat, with a cap buttoned around his ears and a scarf nearly up to his mouth, Crawshay stood there, seeking admittance.

* * * * *

"I am exceedingly fortunate to find you both here," the newcomer observed, as he removed his cap. "Captain, may I have a few minutes' conversation with you and Mr. Dix?"

"Delighted," the captain acquiesced, "so long as you don't keep me more than twenty minutes. I am due on the bridge at nine o'clock."

"I will endeavour not to be prolix," Crawshay continued, carefully removing his rubbers, unfastening his scarf and loosening his overcoat. "A damp night! I fear that we may have fog."

"This all comes off the twenty minutes," the captain reminded him.

Crawshay smiled appreciatively.

"Into the heart of things, then! Let me tell you that I suspect a conspiracy on board this boat."

"Of what nature?" the captain asked swiftly.

"It is my opinion," Crawshay said deliberately, "that the result of the whole accumulated work of the German Secret Service, compiled since the beginning of the war by means of Secret Service agents, criminals, and patriotic Germans and Austrians resident in the States, is upon this ship."

"Hell!" the purser murmured, without reproof from his chief.

"It was believed," Crawshay continued, "that these documents, together with a letter of vital importance, were on the steamer which conveyed the personnel of the late German Ambassador to Europe. The steamer was delayed at Halifax and a more or less complete search was made. I was present on behalf of the English Embassy, but I did not join personally in the search. You have all heard that the seals of a tin chest belonging to a neutral country had been tampered with. The chiefs of my department, and the head of the American Secret Service, firmly believe that the missing papers are in that chest and will be discovered when the chest is opened in London. That is not a belief which I share."

"And your reasons, Mr. Crawshay?" the captain asked.

"First, because Hobson and I were decoyed to Chicago by a bogus telegram, evidently with the idea that we should find it impossible to catch or search this steamer. Secondly, because there is on board just the one man whom I believe capable of conceiving and carrying out a task as difficult as this one would be."

"Who is he?" the captain demanded.

"A very inoffensive, well-mannered and exceedingly well-informed individual who is travelling in this steamer under, I believe, his own name—Mr. Jocelyn Thew."

"Jocelyn Thew!" the captain murmured.

"Thew!" the purser repeated.

"Now I tell you that I have definite suspicions of this man," Crawshay continued, "because I know that for some reason or other he hates England, although he has the appearance of being an Englishman. I know that he has been friendly with enemy agents in New York, and I know that he has been in recent communication with enemy headquarters at Washington. Therefore, as I say, I suspect Mr. Jocelyn Thew. I also suspect Robins, the wireless operator, because I am convinced that he has received messages of which he has taken no record. I now pass on to the remainder of my suspicions, for which I frankly admit that I have nothing but surmise. I suspect Mr. Phillips, Doctor Gant and Miss Katharine Beverley."

The last shock proved too much for the captain. For the first time there was distinct incredulity in his face.

"Look here, Mr. Crawshay," he protested, "supposing you are right, and that you are on the track of a conspiracy, how do you account for a physician from the finest hospital in New York and one of the best-known young ladies in America being mixed up in it?"

Crawshay acknowledged the difficulties of the supposition.

"As regards the physician," he said thoughtfully, "I must confess that I am without information concerning him, a fact which increases my suspicion of Robins, for I should have had his dossier, and also that of the man Phillips, by wireless twenty-four hours ago."

"What about Miss Beverley then?" the captain enquired. "Her family is not only one of the oldest in America, but they are real Puritan, Anglo-Saxon stock, white through and through. She has a dozen relatives in Congress, who have all been working for war with Germany for the last two years. She also has, as she told me herself, a brother and four cousins fighting on the French front—the brother in the Canadian Flying Corps, and the cousins in the English Army."

"There I must confess that you have me," Crawshay admitted. "What you say is perfectly true. That is one of the mysteries. No plot would be worth solving, you know, if it hadn't a few mysteries in it."

"If you will allow me a word, Mr. Crawshay," the purser intervened, "I think you will have to leave Doctor Gant and his patient and Miss Beverley out of your speculations. I have our own ship doctor's word for it that Mr. Phillips' condition is exactly as has been stated. Mr. Jocelyn Thew may or may not be a suspicious character. Anything you suggest in the way of watching him can be done. But as regards the other three, I trust that you will not wish their comfort interfered with in any respect."

"Beyond the search to which every one on board will have to be subjected," Crawshay replied, "I shall not interfere in any respect with the three people in question. Mr. Jocelyn Thew, however, is different. He is a man who has led a most adventurous life. He seems to have travelled in every part of the globe, wherever there was trouble brewing or a little fighting to be done."

"Why do you connect him with the present enterprise?" the captain asked.

"Because," Crawshay answered, "the wireless message of which your man Robins took no record, and concerning which you have kept silence at my request, was delivered to Mr. Jocelyn Thew. Because, too," he went on, "it is my very earnest belief that at somewhere in the small hours of this morning there will be another message, and Mr. Jocelyn Thew will be on deck to receive it."

The captain knocked out the ashes of his pipe a little apprehensively.

"If half what you suspect is true, Mr. Crawshay," he said, "you will forgive my saying so, but Jocelyn Thew is not a man you ought to tackle without assistance."

There was a peculiar glitter in Crawshay's deep-set eyes. For a single moment a new-born strength seemed to deepen the lines in his face—a transforming change.

"You needn't worry, Captain," he remarked coolly. "I am not taking too many chances, and if our friend Mr. Jocelyn Thew should turn out to be the man I believe him to be, I would rather tackle him alone."

"Why," Mr. Dix demanded, "should anything in the shape of violence take place? The ship can be searched, every article of baggage ransacked, and every passenger made to run the gauntlet."

Crawshay smiled.

"The search you speak of is already arranged for, Mr. Dix," he said; "long cables from my friend Hobson have already reached Liverpool—but the efficacy of such a proposed search would depend a little, would it not, upon whether we reach Liverpool?" "But if we were submarined," the captain pointed out, "the papers would go to the bottom."

Crawshay leaned forward and whispered one word in the captain's ear.
The latter sat for a moment as though paralysed.

"What's to prevent that fellow Robins bringing her right on to our track?" Crawshay demanded. "That is the reason I spent last night listening for the wireless. It's the reason I'm going to do the same to-night."

The captain sprang to his feet.

"We'll run no risks about this," he declared firmly. "We'll dismantle the apparatus. I'd never hold up my head again if the Von Blucher got us!"

Crawshay held out his hand.

"Forgive me, Captain," he said, "but we want proof. Leave it to me, and if things are as I suspect, we'll have that proof—probably before to-morrow morning," he added, glancing at the chart.

There was a call down the deck, a knock at the door. The captain took up his oilskins regretfully.

"You will remember," Crawshay enjoined, "that little mandate I showed you?"

The captain nodded grimly.

"I am in your hands," he admitted. "Don't forget that the safety of the ship may be in your hands, too!"

"Perhaps," Crawshay whispered, "even more than the safety of the ship."