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!