The morning after the walk in the snow-storm Lucy was alarmed to find Bob pale, tired and strangely preoccupied. He would hardly answer her questions, and his weariness and obvious anxiety were both greater than the events of the day before could explain. Lucy asked him, troubled enough herself without this added vexation:

“Is there anything new, Bob? Won’t you tell me? Or do you really feel worse?”

“My leg hurts a bit, but not enough to worry about. Don’t bother, Lucy, I’m all right.”

Nothing more could she get out of him, and she had too much to decide for herself to spend any longer time coaxing his confidence.

It was Wednesday, and not a holiday for her, but immediately after luncheon she went to Miss Pearse and begged the afternoon off duty. This was the harder as she did not want to explain her plan to anyone in the hospital, and least of all did she want any hint of it to reach Bob’s ears. Today was the day of Elizabeth’s rendezvous, according to the letter which Lucy had reread half a dozen times over the night before by her bedroom candle. If she was to discover her old nurse’s secret she must act to-day, and without Bob’s help, for she was convinced that he was suffering again, and not for anything in the world would she have tempted him to fresh activity.

Miss Pearse was surprised at Lucy’s request, but did not refuse consent. “Where are you going?“ she asked. ”To Coblenz? You’ll want the whole afternoon, then. I’ll have to take away your Thursday half-holiday.“

“Of course, I meant you to. Oh, Miss Pearse, thanks ever so much. I’ll work twice as hard.”

Miss Pearse laughed, for this was one of Lucy’s old habits, to run away from her duty on some adventure and make up for lost time later by a tremendous burst of energy. “Be back by supper time,” she said, nodding good-bye.

Lucy had found out earlier in the day that a motor-truck was leaving the hospital soon after luncheon for Badheim with some of the convalescents. The driver promised to take her on to Coblenz. Her plans were vague enough. After turning over Elizabeth’s strange conduct in her mind until she was weary she had come to no conclusion. Her one purpose now was to see Elizabeth, if possible, and, that failing, to find Larry and ask his help in place of Bob’s.

By three o’clock the truck left her at the door of her father’s house. It was a fine, sunny winter afternoon. The snow sparkled on the ground and the air was clear and bracing. The streets were crowded with people, many of whom stopped, with German inquisitiveness, to stare at Lucy as she waited on the door-step.

The door was opened by an orderly who greeted her with, “Oh, Miss, I’m sorry. The General went out an hour ago. He didn’t say when he’d be home.”

“Where’s Elizabeth?” asked Lucy, her pulse quickening with the words.

“Elizabeth’s out, too, Miss. She asked leave of the General this morning. Gone to see a friend, I think.”

Lucy entered the house and, going into her father’s study, sank down in his chair and caught hold of the telephone, thinking hard a minute. Elizabeth’s absence made things real. There was no more time for hesitation. She called up Larry and, to her tremendous relief, heard his voice answer.

“Larry, it’s Lucy,” she said hurriedly. “I’m at Father’s. Can you come here a minute? I wouldn’t ask you if it were not——”

“Of course I’ll come,” Larry interrupted. “Why the excuses? I’ll be there in a jiffy.”

He rang off and Lucy sat waiting, trying to piece her plan together as she fingered the letter once more withdrawn from her pocket.

“At nightfall,” she repeated to herself. “That means four or half-past. We haven’t much time to lose.”

In a quarter of an hour the bell rang, and Lucy, going to the house door, found Larry on the steps.

“Hello, Larry. Thank you lots for coming. Let’s walk, shall we? I’ll explain as we go,” she said, all in a breath.

The next moment they were threading their way along the street, Larry’s blue eyes turned on Lucy with a curiosity that refused to be suppressed. “I’m all ready to hear about it,” he said. “Which way shall we go?”

“Larry, can you get a launch? You told me the other day you took Colonel Wigmore’s when you needed one.”

“Why, yes, I can get one. What for?”

“Where is it? Let’s walk in that direction.”

At Lucy’s earnestness Larry glanced keenly at her and answered, “All right. Come straight across town to the Embankment. There ought to be a launch along there that I can pick up. Where do we go in it?”

Lucy handed him Elizabeth’s letter saying, “Read that. I found it in the pocket of Herr Johann’s coat yesterday. Bob is tired out and his leg hurts him. I wouldn’t let him know for anything. That’s why I’m begging you to help me. I want to follow Elizabeth and see where she goes. You and I have often gone out on the river for an hour. No one need know the truth. We’ll find out why Elizabeth meets Franz. If she’s all right, I want to know it, and if she isn’t——”

Lucy’s voice shook a little. She was too fond of Elizabeth to face the discovery of her treachery without real sorrow. Even now she could not believe in it, and her thoughts wavered wretchedly between doubt and confidence.

“Larry, I don’t think she would deceive us! I can’t believe it!” she cried, as Larry finished reading Elizabeth’s note and handed it back to her.

“Hum—looks queer,” was his comment. Then, after a moment’s silence, “All right, Lucy, we’ll go. And I’m going to take someone else along. You won’t mind when you see who it is.”

He turned to beckon to a passing soldier as he spoke and Lucy did not hear his last words. They were nearing one of the tree-bordered walks of the Rhine Embankment.

“Look, there’s an airplane,” said Lucy, pointing across the river.

Larry said a word to the soldier which sent the man, with a quick salute, down a near-by street. Then he showed Lucy a motor-boat moored to a little wharf at the river’s edge. “I suppose I’m wasting my breath, Lucy, when I ask you to stay here and let us go on the wild-goose chase?”

“Us? Who’s us?” said Lucy, ignoring the proposal. “I don’t want anyone else to know.”

“You won’t object to Harding, will you?”

“Major Dick Harding? Is he here? Is he coming?” cried Lucy, forgetting for a moment her anxiety.

“Yes. Got here this morning. You remember Bob wrote him asking about von Eckhardt? He’s come with quite a bit of news, including some that will prove Bob a good guesser. Here he is now.”

Major Harding came swinging along at a quick walk, and his face lighted up at sight of Larry’s companion.

“How are you, Captain Lucy?” he exclaimed, holding out his hand. “I thought you were in Badheim. I was going out there to see you. What are you doing here?”

“We’re waiting for you, Major Harding,” said Lucy, her excitement returning with the recollection of her strange errand. “We need your help.”

Major Harding glanced quickly from her to Larry for confirmation. Larry nodded, then said, “Will you come out on the river with us, Harding? There’s the boat. We’ll explain as we go. Lucy’s got something up, as usual.”

Major Harding agreed and asked not another question until the motor-boat’s crew had pushed off from the dock and the swift little craft was moving up-stream with its three passengers. Then Larry handed him Elizabeth’s letter, and repeated all he himself knew of Elizabeth’s relations with Franz and Herr Johann.

“We’re off on their trail now,” he finished. “We’d no time to explain to you on shore. What do you think, Harding? Lucy can’t believe Elizabeth is up to mischief.”

Lucy was watching the Stars and Stripes floating over the giant fortress of Ehrenbreitstein, just across the river. Now she lowered her eyes to Major Harding’s face.

He answered thoughtfully, “I can hardly believe it either, that Elizabeth has turned traitor. Yet how to explain this——” He glanced at the note in his hand. “As for von Eckhardt, I told you, Eaton, what I know of him. He’s one of the most bitter malcontents in Germany. He has lost everything with the Kaiser’s fall and he hates the Republican government. He would league himself with no matter which enemy of ours now—anything to break up the Allies and delay the peace.”

“But how? What can he do?” asked Lucy, feeling once more as though it were only a dream that the war was over.

“Lots of ways,” said Major Harding. “Fortunately we’re on to the way he adopted, and I don’t think, as I told Larry, that he’s got very far. What he’s doing here is only a small part of his plottings throughout Germany. He’s a clever rascal.” He spoke low, glancing at the steersman.

“Well, what is he doing?” asked Lucy, her heart thumping as she put the question.

Major Harding saw her flushed face and laid a friendly hand on her arm, saying, “You’ll hear it all soon enough. Let’s decide what we have to do now. To begin with, how is your precious Elizabeth going to get across the Rhine? And how are we to know her landing-place?”

“I’ve thought of that,” said Larry. “She probably crossed on one of the barges that take over Franz’ wood. As for the landing-place, we’ll have to look for it. Five miles up, she said.”

As he spoke the boat sped past the village of Cappellen, the castle of Stolzenfels towering on the hill three hundred feet above. Twilight began to darken the river and from the banks stray lights shone out. A torpedo boat cast its gleaming search-light over the water. The broad stream was almost deserted, a few scows were being towed along, and a river steamer passed, going toward Mayence.

“We’d better go inshore, before it gets dark,” Larry suggested. “We’ll have to trace them by the wood-barge. When I think of Franz and his honest labors!” Larry gave a sudden snort of indignation. Then to the steersman he ordered, “Go inshore and turn the search-light along the bank. Are we five miles south of Coblenz?”

“Yes, sir, within a half-mile,” the man answered.

“This is guesswork, Eaton,” Major Harding protested. “We can’t scour a mile of river shore in the dark. Before we stumble on them they’ll have had their talk and gone home.”

“It’s not so hard as you’d think,” declared Larry. “I know the banks pretty well along here. Don’t throw the search-light over the shore, Ed,” he directed the man by the steersman’s side.

The boat was drifting now, in the shadow of the bank. Night had fallen and the moon was rising over the steep hillside that loomed above them.

“See there, Harding?” Larry continued, pointing inshore. “All along here are rocky or wooded slopes. Do you see the bushes growing low along the bank? There are no vineyards for half a mile further. It’s fairly deserted. We have only to find the barge they came in.”

“There’s a light, Larry,” Lucy whispered, her heart hammering with nervous excitement. “What can it be?”

“It’s a house near the little hamlet below here, Altheim, I think it’s called. Shut off your search-light, Ed.”

“There’s a barge, sir,” said the steersman, pointing ahead.

The boat’s passengers stared into the darkness, faintly lighted now by the moon touching the water with phosphorescent gleams. Along the dark line of the shore a darker blot showed, and, as the boat floated nearer, a big, heavily-loaded barge came into sight, fastened to one of the small trees growing near the bank, and somewhat hidden by the bushes’ low-growing bare branches.

“Push in here, Rogers,” Larry ordered. “Can you make a landing?”

“I think so, sir. Throw a light on, Ed. Why, yes, sir, here’s a bit of a dock.”

He cautiously floated the boat inshore and moored her alongside a little plank landing-stage.

“We must be near the hamlet,” said Larry. “Yes, there are the lights,” he added, parting the bushes and peering up the slope.

He sprang out, followed by Major Harding, who gave Lucy a hand, saying doubtfully: “I don’t like your going with us, Lucy. I don’t know where we are going, for that matter.”

“Up to the hamlet,” said Larry. “Or not really to it, but to that lonely little cottage this side of it. We’ve only a hundred yards to climb.”

“I’m not afraid, Major Harding,” said Lucy, still whispering. “I can’t feel frightened at meeting Elizabeth.”

“Come on,” said Larry, leading the way over the rough, rising ground. “Ed, you come, too. Rogers, stay with the boat.”

“How do you know they are in that cottage?” asked Major Harding. “While we’re climbing the hill they may give us the slip.”

“I don’t know why I’m sure, but I am,” declared Larry, refusing to be deterred. “Don’t you see what an ideal place it is for a secret meeting? And though it’s so lonely, they’ve taken the added precaution of lighting only one candle. Compare that faint glimmer with the lighted windows of the hamlet. And it’s the nearest house to the landing-stage. How are you, Lucy? Need a helping hand?”

“No, I’m all right.”

They had begun climbing the steep hillside, which was rocky underfoot, for the snow had barely clung there, with thickets at intervals, and groves of small trees rising black and bare in the moonlight. In ten minutes they neared the little house perched on the slope, with beside it a tiny orchard growing on a bit of fairly levelled ground. All was silent around it, and all dark, but for the moon, the lighted window hidden now by a turn in the rocky path.

Lucy stopped, panting, in front of the cottage, and looked back down the slope at the broad, shining river, and inshore at the dozen twinkling lights of the hamlet. The wind was blowing over the heights with wintry bleakness. A shiver of cold and apprehension caught her, but she fastened her coat closer and plucked up her resolution. Major Har............