There are white posts set at intervals along the fen roads to guide travellers in the dark. A necessary precaution as the roads are often ditch-bordered, and for half the year those ditches brim.

The posts are barely two feet in height; by the time the girls had reached the spot where John had left them, only the tops of those posts were left uncovered; the tide was plainly driving in with terrific force, and wherever they looked they saw nothing but the waste of tossing water.

Not one of the three would have owned to being frightened, and it was in quite a cheerful voice that Noreen put their worst danger into words.

"Hurry up, you two. We must get somewhere before the posts cover, or we shan't be able to find the road."

Joey remembered the deep slanting ditches; to slip into one of them had been a very real danger on that foggy Sunday when she had come back alone from Cousin Greta's; to do so now would be almost certain death. She did her best to splash along faster, though she was beginning to feel decidedly conscious that it was a long time since breakfast, and that she was chilled to the bone. It seemed as though the three of them had been splashing through that cold swirly water for years, and there didn't seem any particular end to it; and what had happened to John?

"Where are we going?" she asked dully. "The Round Tower is nearest."

She had to look round, as she spoke, to make sure that the tower was there. All the familiar objects looked so different, standing in this vast sea.

"Yes, it's nearest, but we won't go there," Gabrielle said, in her sensible way. "You see, though it's uncomfortable and very cold to go wading along like this, we are quite safe on the road till the water is a good bit deeper. To try and get across the Deeps with the floods out would be almost as risky as it would have been to try and cross the river just now when it was pouring across the bridge. If we just keep along quietly we shall come to the turning off to Hesgate Church and Rectory, and we can get shelter there till the tide goes down, or someone comes for us."

Gabrielle's matter-of-fact tone had a very cheering effect. She was the smallest of the three, but she was quite the Head of the Lower School just then, and no one thought of disputing her verdict.

"What do you think the others are doing?" Joey asked anxiously. She had been afraid to ask that question before, but Gabrielle seemed so undisturbed by the ways of floods that she felt things could not be as bad as they had seemed.

"I think they will be quite all right," Gabrielle said. "You see Deeping Royal is used to high tides and things of that sort, and people always take refuge in the churches there. The towers were built frightfully strong on purpose. Miss Conyngham once told us about a big flood, in 1830 it was, I think, and the people had to stay in the twin towers all night, while the great waves surged round. One man was so grateful that he gave a new peal of bells to both towers, and put a text on the biggest bell: 'The flood arose, the stream beat vehemently upon that house and could not shake it.'"

"I like that," Joey said.

"Yes, wasn't it decent, and he never gave his name either; he was a stranger in Deeping Royal, and he just sent the bells from London when he had got away safely. The Vicar had 'The gift of a grateful heart,' carved below his text on the bell, and they ring a peal every year on the anniversary of the great flood in memory of him. That day comes in the spring; we always get high tides—special tides, you know—at spring and autumn."

"Well, this one will have come to its highest pretty soon, I expect," Joey said. "You've got a watch, Gabrielle; what's the time?"

Gabrielle looked. "Five past three; and we're just opposite the Round Tower; that means it isn't much more than a mile to Hesgate Rectory. We shall...."

What they might have done remained unknown. There was a curious sound behind them, nothing very loud, but loud enough to make them look round. The water all around them seemed to upheave violently. Instinctively they clung together, and it was a mercy that they did. There was a terrific suck and gurgle about them, and next moment the white posts were all obliterated, and they were swaying helplessly in a great waste of water, which had suddenly grown frighteningly deep. "What is it?" Joey gasped, as the first shock passed, and they found themselves still on their feet, but with the water washing nearly to their waists.

"I don't know," Gabrielle said, staring around her, but Noreen gave a little choke. "You bet it's the reservoir—that weak bank gone—and it's still forty minutes to high tide."

Joey woke up. "We must get across to the Round Tower."

"It's locked, isn't it?" asked Noreen. It was a proof she was inwardly frightened that she did not add, "you juggins!"

"And there's a bad ditch somewhere near it, Joey," Gabrielle added. "We could never find it now."

"I could," Joey spoke confidently. "I've been there, remember. Hold on to me, Gabby; I'm sure I can dodge that ditch; I know where it was."

Gabrielle hesitated for a moment; while Noreen and Joey looked anxiously at her. Every one knew that Gabrielle could not swim. Noreen was not much of a performer; but Gabrielle had been too delicate to learn at all so far.

"We might keep the road," she said; "but we mightn't, and it's a mile. We'll risk the ditch—on one condition, Joey. If we slip—and we'll be going into deeper water anyhow, you know—you and Noreen must save yourselves, and not bother about me."

"We're not going to slip, but we're going to hurry," Joey said. "I'll go in front, because I know the way. You hold on to me, Gabby, and Noreen hold on to you. We'll have to jump the roadside ditch; it isn't a wide one, but it will make a beastly splash. When I say Now!"

They turned sideways. "Now!" shrieked Joey. They all jumped, and Noreen failed to clear the ditch, and had to be pulled out, spluttering and choking, by the other two.

They had landed in water that was more than waist high, for the road was raised. The question was how much more the fen dipped before they reached the tower. Joey plunged on, but cautiously, putting one foot well in advance of the other, in terror of that yawning ditch. It was all very well to say so confidently that she remembered its exact position; how was one to be sure of the exact position of anything with all the world water, and a sense that at any moment one might step clean out of one's depth? Joey had swum well out of her depth on the last seaside holiday the family had shared, but then Father was beside her to call, "Steady! and don't hurry your stroke"; and "Put your hand up on my shoulder," when she was getting tired. Swimming now would be a very different matter with Noreen, who had only just achieved the width of the Redlands swimming bath last summer, and Gabrielle, who was helpless, to bring to safety besides herself. All the same she never thought for an instant that she might not be able to do it; that sort of thought was not for English people. One just must.

The tide was rushing in at a truly terrific pace, but the three, gripping desperately to each other, kept their footing and struggled on. And so, after what seemed an eternity of nightmare struggling through the deepening water, they flung themselves against the wall of the Round Tower at last.

"Hold on, Gabby; I have to find the door," Joey cried cheerfully. The worst was over now, she thought; the tower floor was well raised, and inside there was a ladder. She waded round to the narrow ledge, scrambled up, and felt the door.

It was bolted as before, and this time she had no knife in her pocket. To be accurate she had no pocket in her djibbah; when she had begun this long queer day her handkerchief had been up her sleeve. Now it was probably whirling hither and thither about the Deeps.

Joey stooped a little, and put her mouth to the chink. She must make the young man hear.

"I say, do let us in. We're outside your door."

She had shouted at the top of her voice, and she got an answer, though it was not the answer she expected. It was a queer muffled cry, but it was a word, and the word was "Help!"

Joey looked down from her slippery stand upon Noreen and Gabrielle. Gabrielle was shoulder deep; she was clinging silently to the rough wall of the tower, but there was nothing much to take hold of. Joey must get the door open and go to her help at once.

"Got a knife, either of you?" she jerked at them.

"I have," called Noreen.

Joey did not dare tell them to move from their precarious position. The water was washing hard against the tower; Gabrielle at least could be washed away from it quite easily if she loosened her grip.

"Chuck it here!" she shouted, and prayed that she might not muff the catch. Noreen fumbled and threw. Joey, leaning a little away from the door, with one hand clinging, caught the knife as it flew across the water, and held it—safe!

She had it open in a second, and forced the bolt a minute later. Kneeling in the doorway, she undid her braid sash, meaning to fling it out to Noreen and Gabrielle.

"Get hold; we're all right now."

And as she spoke she heard again that muffled call for help from somewhere underneath. Then, of course, she remembered her first visit, and the jumpy young man who had come up through the trap-door.

The floor of the Round Tower was hardly under water yet; but what was it like underneath? That last call had been the choked effort of someone who couldn't breathe.

Joey stood irresolute for one second—but only one. The jumpy young man was probably a German, since he and the Professor had been signalling to one another; but when you were English you couldn't leave even a Hun to die when he had called for help. Father had risked his life to bring in a wounded German who was lying in agony in a shell-swept reach of No-Man's Land. She would not even have hesitated for that second, if it had not been for the thought of Gabrielle and Noreen holding on precariously, with the deepening water washing round them, waiting for her help. In her heart she knew that her friends would not want her to hesitate.

She darted across the floor to the corner where the trap-door was, and then she saw what had happened. The owner of the tower had been right in considering it rather shaky, and none too safe. A great stone had come down, and lay upon the trap-door, making it quite impossible to push up from below.

Joey flung herself upon the great stone. "All right—I'll get it open," she shouted; but there was no answer. That faint choked call was not repeated.

She pushed at the stone with all her strength, but it did not budge. She pushed again, with a terrible nightmare feeling that Gabrielle, her friend, could not keep her footing in the water, and was drowning while she wasted time. She took a deep breath, and pushed, with cracking muscles, for the third time, and the stone rolled over with a loud splash, and the trap was free.

"Can you push?" she shouted. When she had seen him before the young man had come up a ladder propped against the side, and pushed the trap up from below. But now there was no sound or answer. Joey thought of Gabrielle's story of the man who had been drowned in the room below the Round Tower in just such another flood, and hunted desperately for something she could catch at and pull the trap-door up.

She found a ring at last, and tugged with all her might. The trap raised, and water sluiced down into the opening, water that was washing in through the open door. The water from above met the water from below with a great splash. There was no other sound.

Joey peered down the wide trap. Two groping hands and a dead white face with staring eyes showing dimly through the darkness. Black water, of an unknown depth, washed to and fro.

She flung herself face downwards on the edge, and dropped her braid sash straight between the groping hands. "Catch hold!"

The hands fumbled blindly, and then gripped. There was a fierce tug on the impromptu rope. Joey dug her toes into the floor, in the effort to escape being pulled in.

"That's right, hold on, and get to the ladder," she shouted. "Make haste."

She looked at the side where the ladder had been; it was gone! And the water below was still a good long way below the level of the floor, and the trickle washing in would not raise it till too late for Gabrielle and Noreen.

Joey looked round desperately for something to which she could secure one end of her sash. At all costs she must hurry to the help of the other two. But there was nothing at all, nothing except the ladder on the farther side of the tower, fixed to the wall; and to reach that would require a sash of treble the length. No, there was only one thing to be done, unless she meant to abandon the young man to his fate—and one couldn't let an enemy drown when one was a soldier's daughter.

"It's all right. I'll pull you up; but please keep quiet and don't jerk, or you'll drag me in," she called down, trying to speak confidently. "Don't start to come up till I say 'Now'!" she added hastily, as a frantic jerk to the rope all but had her through the trap.

She slithered back over the floor to the farthest extent her sash would give her, and got behind the stone that she had moved with so much difficulty. Then she looped the end of her sash, got a desperate grip, took a long breath, and shrieked "Now!"

It was a frightful tug. Her straining body pushed the heavy stone with it nearer and nearer to the edge. Her hands seemed as though they were being wrenched away from her wrists, and her arms from her shoulders. The toes and her knees scraped the stone of the floor as she dug them in fiercely to gain hold, and she was dragged forward all the time. It never occurred to her to let go, but she knew vaguely that it was only a question of seconds before she went through the trap for all her efforts. And then a hand caught the edge of the trap, and the strain slackened suddenly.

Joey fell backwards, and lay there panting and speechless for a second, while the young man exhaustedly dragged himself up to safety. But she only lay for one moment; then struggled up and to the door.

Her heart was thumping with hammer strokes; she felt sure that she would not see her friends. It seemed such years that she had been wrestling with the trap-door, and trying to grip on to that slippery sash.

But they were there; clinging tightly—Noreen with her arm round Gabrielle, both with their heads turned anxiously to the door. Noreen spoke quite cheerfully, though with chattering teeth.

"I say, buck up with that sash, you juggins!" she grinned. "We're getting wet."

Joey didn't answer, because there was such a lump in her throat that she couldn't. She threw the pulled and ravelled sash, and Noreen caught it. Steadying themselves with it and the wall of the tower she and Gabrielle came safely to the door, and scrambled up into the tower.

Joey hugged them both, regardless of the young man's presence. "Oh, you dears!"

"What made you such an age?" Noreen inquired. "Did you stop to explore the tower or something?"

The young man answered the question. "She saved my life. I was suffocating there, and drowning, and she pulled me up. I owe her my life."

"Oh, that's all right," Joey said, rather flustered. "Anyone would have lent a hand, of course. But do you mind telling us now whether you are in league with our Stinks Professor—you signal to him, don't you? But I hope you aren't doing beastly things like poisoning water, for you don't seem that sort."

The jumpy young man stared at the three Redlands girls, till his eyes seemed ready to start from his head. Then he gasped, "How do you know?"

"Because we've got the Professor—at least I think John has—and anyhow we've spoilt his game," Joey announced triumphantly. "But we want to know if you've been doing those kind of beastly spy things too—because we don't want to be hateful, but we couldn't shake hands with you and be friends if you have!"

They stood ankle-deep in the water, and stared at one another, Joey and the man whose life she had saved. There was a dead silence for a whole minute; then he said:

"I have worked with him, and I knew something of his plans, but mon Dieu! how I hated them and him. For my home is in Alsace, and my father and mother were French. The Professor, who is no more French than you are, had lent my father money, and I was to work it out as his assistant. And since the War he has forced me to work for him in this country, knowing I was too much implicated to betray him. And that is the truth, Mademoiselle."

Joey held out her hand. "You'll chuck it now, of course, and I'm sure Colonel Sturt will see about your not getting into trouble; and, if you don't mind, I could speak to Mademoiselle de Lavernais about you—she comes from Alsace too. We're no end glad you're all right, really."

"Rather!" said Noreen and Gabrielle with great heartiness, and all three shook hands with the Alsatian solemnly.

"What's your name?" asked Joey, feeling that she ought to act as mistress of the ceremonies in right of her former acquaintance with the jumpy young man.

"I was baptized 'Hans'; when the doors and windows were all shut my parents called me 'Jean,' 'Jean Corvette,'" he said.

"Righto, we'll call you that," Joey said. "I thought you couldn't be a Hunnish kind of German when you were so decent to me that Sunday, you know. We'll introduce ourselves, and then it will all be as right as rain. This is Gabrielle Arden, and here's Noreen O'Hara, and I'm Joey Graham."

Two drowned rats bowed politely in acknowledgment of Joey's introduction; but the jumpy young man was not looking at them. He was staring at Joey.

"Graham—Graham—" he muttered; then suddenly: "I was with the gardeners that night you act in the big hall, and you have the look of him then, Mademoiselle. Was your father a major of the name of Graham?"

"Yes, he was; but the Huns killed him with their beastliness to him when he was wounded and a prisoner," Joey said.

"You saved my life; I will tell you all I know," the young man said. "When the Professor sent for me to come here, two months ago, Major Graham was not dead, but alive and working in the salt mines at Kochnecht."

"What?" Joey gasped. "He was reported killed."

"Many are reported so, but not all are dead. Some day perhaps a search will find Englishmen left behind in Germany. Your Major Graham is one—I gave him water when he was wounded, and no woman would have pity, and he thanked me and said I was 'a good chap,' and smiled as you smile, Mademoiselle, so I remember him. But the Count that used to shoot at Calgarloch Castle had a spite against your father, and returned him 'killed.'"

The tower room swam with Joey for a moment; she felt sick and queer.

"I say, you're not going to faint or anything rotten like that, are you?" cried Noreen; "because it's a beastly damp place to do it in."

"Don't, Noreen, it's her pater." That was Gabrielle speaking. Joey pulled herself together.

"I'm all right—only it's ... it's so heavenly. Did you hear, Father's alive!"

Noreen seized her round the waist. "Yes, I heard, and it wasn't heartlessness, only you did look funny for a minute. Joey, I am glad; and isn't it queer and topping that everything's gone and happened like this. If there had been no flood, or John had driven us to Deeping Royal as he intended, we should have been up the twin towers with the rest, and you would never have heard this."

"And if I hadn't been caught in the sea-roke that Sunday, and known you were down the trap-door, I shouldn't have known where to look for you when you called 'Help!'" Joey said to Jean Corvette.

"And if you had not risked your life to rescue me, Mademoiselle Joey, I should never have talked again," he said.

"And if we hadn't been Joey's special friends and waited for her at the reservoir, I suppose the old Professor would have got away, and most of this wouldn't have happened," Gabrielle suggested seriously. "We're all very wet, and Matron will be cross to-morrow; but it's all been gloriously worth while."

"Hasn't it just!" Joey cried ecstatically. "And now, if Jean doesn't mind, let's get up that ladder. You bet John will be looking out for us as soon as he has settled the Professor, and I know he had some plan when he said he would drive him."

Jean made no objection, though he was still too much exhausted to go with them. But the three friends, undeterred by wet and clinging garments, climbed the shaky ladders to what was left of the top floor of the tower, where they found the electric torch which Jean must have used lying close under a loop-hole window.

"Of course a torch-flash isn't easy to read in daylight, but there's no sun, and it's getting darker," Joey suggested.

"Then it must be past high tide," Noreen said joyfully. The three stood at the loop-hole, looking out for a minute in silence over the dreary grey waste of water. A wicker hen-coop and a large bath-tub washed aimlessly about near the walls of their refuge, farther off a poor drowned sheep showed, half submerged.

Gabrielle put her arm through Joey's. "We might have been drowned too," she said, "and instead we're all right, and your father's alive."

Joey couldn't answer that for a second: then she said huskily, "Thanks awfully, and I am glad we're all in it together."

"And always will be for ever and ever, Amen," chipped in Noreen the irrepressible. "Gabrielle will be Upper School next term, Miss Craigie thinks, but she'll never desert the alliance, I know. It's going to be for always."

"I say, I am jolly glad I came to Redlands," Joey said from her heart.

They took turns after that to work the torch, sending S.O.S. signals out into the wet world, while the tide steadily sucked back and back, leaving the tops of the white posts uncovered once more. And then over the grey waste a boat came, and they tore down the ladders at a breakneck pace to welcome John, rowed by a sturdy policeman.

"What's happened to him—the Professor?" shrieked Noreen, as soon as the boat came into hailing distance.

"Oh, you're all right, you three, thank goodness!" John sent back, as he steered the boat carefully for the tower door. "I felt rather jumpy about you, when the sea burst in. But I might have known Joey would come out top. The Professor?—oh, he is safely in the lock-up, with his violet handkerchief—which it seems is the secret insignia of his crowd—and his precious bugs. The flood was really a convenience, otherwise I meant to run my car into a ditch, and have him that way if poss. As it was, the tide burst in and swamped us, and he can't swim and was in a blue funk of drowning, so I had no bother at all. Just left him hanging on to the car, without his bugs, revolver, or hanky, and swam for help. I could have waded, of course, but swimming was easier for my game leg, and more impressive. And they're all right at Deeping Royal; they're sending boats. So you have nothing to do, but to let us get you back to Redlands."

Hanging on to the door, Joey stooped to whisper to John. "John, be nice to this man here, because he's told me Father is alive in Germany."

"What, your pater alive after all! Top-hole!" John said. "That will be something to tell Aunt Greta!"

Joey looked back at the Round Tower, as she and the rest were rowed quickly away from it. How little she had guessed, when she had first come to Redlands, and looked at it with so much interest, what it would mean to her!

That night, while a disapproving Matron, armed with an immense bottle of sal volatile, stood by, urging bed for everyone, Joey Graham was cheered at tea by the entire school.