Aaron Rodd clasped his arms a little further around the barrel against which he was leaning, trod water with his feet and thought about death. The curtain of a slight mist had fallen around him. There was nothing visible but the cold, grey sea, sometimes high above his head, sometimes like a water-slide tumbling away many feet below him. All around him he could hear the hooting of the steamers, sounding their weird notes of warning from some unseen, unimaginable world. A few feet away, also clinging to a barrel, was a bronzed and hairy man in nautical attire, who was using the most awful language.  
"No good wasting your breath," Aaron gasped. "Try another shout."
 
The man did as he was advised, without eliciting any reply from the other side of the grey walls, whereupon he proceeded once more, in lurid language, to express his opinion of murdering foreigners, and mysterious gents who tempted honest tug-masters into doubtful enterprises. Suddenly he broke off.
 
"Crikey! 'Ere's something on the top of us!" he exclaimed. "Shout, guv'nor, quick!"
 
Once more Aaron Rodd drew a long breath and shouted. His voice sounded like a child's falsetto, lost in the stentorian roar of his companion's demand for immediate help and rescue. Then the grey fog was suddenly pierced. A huge, dark mass seemed to be gliding almost on the top of them. From somewhere up in the clouds came an answering shout. Aaron Rodd's companion was moved to one supreme and successful effort. A clear, loud voice shouted directions to them.
 
"We're lowering ropes. Catch hold, if you can, before the wash. We'll lower boats in a minute."
 
Half a dozen ropes came down like curving snakes. One of them hit the water scarcely a foot from Aaron. He gripped it tightly.
 
"Twist it round your body, mate," his companion spluttered. "Twist it two or three times round and hold on for dear life."
 
The next few minutes were barely realisable. Aaron felt himself tossed like a cork on to the top of a seething mass of churned-up sea, flung down again with the roar of it in his ears, left for a moment in peace and then dragged through the water at such a pace that he found himself wondering whether his arms were going to be torn from his body. Then he was shot forward with a new impetus. His body and arms ached with the strain. He was only half conscious.
 
"That's done it, matey," he heard his companion shout. "Hold on, there's the boat coming."
 
Aaron Rodd never wholly lost consciousness. He heard the measured beat of the oars, the sharp, clear voice of the officer standing up in the stern. He saw the boat emerge from the gloom, heard the quick orders, felt himself lifted up by the shoulders, felt the luxury of something solid beneath his feet. The officer in charge of the boat looked at the two men curiously.
 
"What's this?" he asked. "Collision?"
 
Aaron Rodd's companion took a long breath and tried to explain what it was. The officer listened to him, spellbound. The men almost forgot to row.
 
"Some one seems to have been playing a dirty trick on you, eh?" the former remarked, when at last the mariner ceased through sheer exhaustion. "Well, you can tell the Commander when we get on board."
 
Gradually a fuller consciousness returned to Aaron Rodd. He was able to walk along the deck of the ship they boarded, to grope his way, unaided, down the narrow stairs into the small cabin below, where a man was seated at a table with a chart before him. He pushed it away as the two men were ushered in.
 
"Hullo, what's this?" he exclaimed.
 
The officer who had brought them made a brief report. The Commander nodded.
 
"Fetch them some hot whisky, quick," he directed. "Now tell us your story."
 
The tug-master got in first, but after a few sentences the Commander stopped him.
 
"I think I'll get at the truth quicker from you," he decided, nodding to Aaron. "Quick, please."
 
Aaron pulled himself together and took a long gulp of the hot whisky which was at that moment brought in.
 
"May I enquire if this is an English man-of-war?" he asked, as he set the glass down.
 
"His Majesty's destroyer, Flying Fox," was the brief reply. "Now tell me what you two men are doing on barrels in the North Sea?"
 
Aaron Rodd found a few terse and explicit words.
 
"Early this morning," he said, "I escorted a young lady to Tilbury. We went there on the strength of a bogus telegram, which informed us that her brother, who is a Belgian officer, was leaving there at midday on a munition ship bound for Havre. We found a ship's boat waiting for us at the dock mentioned in the telegram, but they refused to take me on board with her. I thought this reasonable, as it was supposed to be a Government vessel, and I stayed behind to wait for her. She was no sooner safely on board than the steamer hoisted the Norwegian flag and steamed off."
 
The Commander stared for a moment. Then he looked away.
 
"Sounds a queer story," he observed.
 
"It's a true one," Aaron assured him. "Of course, there's a reason for this abduction. The young lady some months ago——"
 
"I don't want the whole story," the Commander interrupted. "I want to know how you got into the North Sea?"
 
"I was coming to that," Aaron Rodd proceeded. "My companion can bear me out as to the rest. I hired his tug, meaning to follow the steamer into whatever port it might go if they refused to take me on board. We caught her up and signalled her to stop. She manoeuvred a little, disclosed a gun, and blew us to pieces. The captain here and I are the only two who ever came up again."
 
The Commander glanced at the lieutenant, who had remained in the room. Not a word passed between them.
 
"Who are you?" he enquired.
 
"My name is Aaron Rodd," was the prompt reply. "I am an American, but I have practised law in England for a good many years. I know my story sounds fanciful, but there's no getting away from the sequel. The tug-master here can confirm every word of it."
 
The tug-master proceeded to do so, and the two officers listened for a time as though fascinated. The Commander interrupted him at last.
 
"What's the name of this boat?" he asked.
 
"She had ss. Christiania painted across her stern," the tug-master said, "and she was flying the Norwegian flag, but the ship's name's new painted. I passed close alongside yesterday, and a queer-looking lot they were on board."
 
The two officers exchanged quick glances.
 
"The Christiania," the Commander murmured softly.
 
He paused for a moment and bent over the chart. Then he looked up.
 
"Take Mr. Rodd and the tug-master to the ward-room," he directed. "Rig them both out in some dry clothes and see that they have everything they want."
 
Aaron Rodd had forgotten the discomfort of his condition. He had only one idea in his brain.
 
"Sir," he told the Commander, "that ship, the Christiania, is in the pay of the Germans."
 
"You may be right, Mr. Rodd," the latter assented. "When you have changed your clothes, come down and have another chat, if I am not on the bridge."
 
Even then Aaron lingered.
 
"Sir," he went on, "I know that there's nothing I can say will keep you for one moment from what you think to be your duty. I have just had a fortune left me in America. I'll give a destroyer to the British Navy if you'll overhaul the Christiania, search her, and take that young lady off."
 
The Commander smiled.
 
"The British Navy doesn't need bribing, sir," he said. "I've had a hint about the Christiania myself. I'll see what can be done. Now off you go and get into those dry clothes."
 
The two unexpected guests were hospitably entertained in the wardroom, and Aaron Rodd made a very creditable appearance, an hour later, in some oddments of naval uniform. They found their way on deck, but were only allowed at the top of the companion-way. The fog had lifted. There were half a dozen steamers in sight, and the destroyer seemed to be completing a rather violent curve. Suddenly there were loud orders. The roar of the machinery was lessened. She glided through the water, slackening speed at every instant. Looking down the deck they could see a sight which thrilled them both. The tug-master understood it better than Aaron.
 
"She's cleared for action, guv'nor!" he exclaimed. "The gunners are all at their posts. See the signal. My God, that's the Christiania!"
 
He pointed to the steamer round which they had circled.
 
"They've signalled her to stop," he continued. "If I get my hands on the captain! ... Hullo, another signal! Watch it, guv'nor. That's the last call—'Heave to at once or'——"
 
"Or what?" Aaron Rodd asked.
 
The tug-master smacked his lips.
 
"Those little six-inch boys will talk," he replied, with gusto. "We could send the Christiania to the bottom in something less than thirty seconds. You watch the angle of those guns. Look at the man's face who's just had an order! He's trained on her. My God!"
 
The Christiania had pursued her course. Suddenly there was a deafening roar, a vibration which shook the ship. Fifty yards in front of the Christiania the sea was all churned into foam.
 
"It's just an 'int!" the tug-master exclaimed in delight. "It's a blankety 'int! Look at 'em running about on board."
 
There were signs of an immense commotion on board the Christiania. Another signal slowly fluttered to the masthead. The tug-master, who was watching the steamer's progress, grinned.
 
"They're giving in," he declared. "They've stopped the engines. Oh, if they'd only let me go on board her!"
 
The lieutenant came running lightly down the bridge and approached Aaron.
 
"We are sending a crew on board the Christiania," he announced. "You'd better go and see if you can identify the young lady. There's a boat being lowered from the other deck."
 
"May I go along, sir?" the tug-master asked eagerly.
 
The officer shook his head.
 
"You stay where you are, my man," he directed. "You'll get compensation for your tug, if your story turns out to be true."
 
The man sighed.
 
"There's two sorts of compensation," he muttered, as he spat upon his hands.
 
Aaron Rodd sat by the side of the lieutenant, and though he had never done such a thing in his life before, he stepped confidently up the rope ladder after him and boarded the Christiania. The captain was waiting to receive them. He was a small, very fair man, who spoke English with a harsh and guttural accent. His manner was exceedingly perturbed.
 
"By what right, will you tell me, this piracy?" he demanded, barely accepting the lieutenant's salute. "My papers were cleared in London. My cargo——"
 
"A few words with you below, if you please, Captain," the lieutenant interrupted. "You had better stay on deck, Mr. Rodd," he added, looking around.
 
Aaron walked up and down and endeavoured unsuccessfully to converse with various members of the crew. The ship bore all the usual evidences of being a small cargo steamer, but there was, to his fancy, something sinister in the appearance of the sailors and the sound of their conversation as they pointed to the destroyer—long, grey and evil-looking, rising and falling upon the waves, a short distance away. Suddenly a man who might have been a steward appeared from below and touched him on the shoulder.
 
"Come this way, please," he invited.
 
He led Aaron downstairs into a dark, odoriferous saloon. The captain and the English lieutenant were seated at the top of one of the long tables. The latter motioned Aaron Rodd to approach.
 
"The captain denies having any passenger on board, Mr. Rodd," he observed.
 
"I saw a young lady taken on board at Tilbury," Aaron pronounced firmly. "She was brought here under a false pretext, and she is here now."
 
"It is not true," the captain declared furiously. "There is no young lady on board."
 
"What do you say to that, Mr. Rodd?" the lieutenant enquired.
 
Aaron leaned a little forward. He stretched out his hand, and the captain for a moment shrank back.
 
"The man is lying," he said calmly. "The young lady was brought here under the pretext of seeing her brother. If this vessel is allowed to proceed on its way to Norway she will be intercepted somewhere by a German boat, and the young lady will be made a prisoner. That is a certainty."
 
"The gentleman has made a mistake," the captain insisted. "There were many vessels lying in the Thames yesterday morning. We do not carry passengers."
 
The boatswain of the destroyer, who had accompanied them on board, entered the saloon and, coming up to the lieutenant, saluted.
 
"Could I have a word with you, sir?" he asked.
 
The lieutenant rose to his feet and retired for a few moments to the further end of the saloon. When he returned, his manner had undergone a change.
 
"Captain Hooge," he said, "in confirmation of this gentleman's story I find that you have two concealed guns on board, and there are other suspicious circumstances which my boatswain has pointed out, which confirm my own impressions about you. I am signalling for a prize crew and shall take you to Harwich."
 
The captain sprang to his feet. His eyes were red with fury.
 
"You damned, meddlesome Englishmen!" he cried. "If you keep me here another hour, you will hear of it! My Government will protest. It is contrary to the accepted principles of maritime law."
 
"It is very much against the principles of maritime law, as I read it," the lieutenant answered coolly, "for you to blow to pieces, with a concealed gun, a tug which simply came up to ask you questions. Now be a sensible man, Captain Hooge. I shall have your ship searched from top to bottom. If the young lady is found, you will have to stand your trial in an English court on an extremely serious charge."
 
"If there is any young lady on board," the captain declared sullenly, "it is without my knowledge. I will go and see the purser."
 
"We will come, too," the lieutenant said dryly.
 
They passed down a little companion-way. The captain opened the door of a small stateroom and talked for some time in Norwegian to a bearded and spectacled man. The latter, after some time, turned towards the two men and spoke in English.
 
"There is a young lady here. She must have boarded us by accident. We were on the point of starting, and we could not land her. Come this way."
 
They followed the man down a long gloomy passage. He knocked at the door of a stateroom at the end of it. A faint voice answered. The door was thrown open. Henriette, white and eager, stood shrinking back against the wall. There was a rush of cold air into the place.
 
"Aaron!" she exclaimed in blank astonishment. "Aaron Rodd!"
 
Words failed her altogether. It seemed too wonderful. She peered into his face, shook him by the shoulders, and finally, almost collapsed in his arms.
 
"It's all right, Henriette," he cried, his own voice shaking. "You're quite safe."
 
"But where did you come from? How did you get here?" she gasped.
 
"I followed in a tug," he told her. "These pleasant people blew us up."
 
"I heard the gun!" she cried. "I saw the tug. I saw it go down! I saw the men swimming in the water. It was horrible."
 
"I was one of them," Aaron continued. "The master and I were picked up by an English destroyer. This is one of the officers. I managed to make them believe my story and we overhauled and boarded your steamer. We are going to take it into Harwich. You are safe, Henriette."
 
She began to sob. The tears stood in Aaron's own eyes as he saw thrust through the open porthole the umbrella on which she had tied various fragments of clothing.
 
"I have been waving this out of the porthole," she explained hysterically. "I thought t............