So Mr. Knight, walking along the cliffs above them, even had he peered down to the lower level, could hardly have seen them. His "Young ladies, young ladies, we're starting home now," grew feebler and feebler, and when Martine had assured herself that he was really a safe distance away, she came out from her hiding-place with a cry of "Danger past." "We mustn't stay here too long," remonstrated Priscilla; "Mrs. Redmond will be worried." "I am perfectly willing to go now," replied Martine, "since Mr. Knight won't lead me by the nose. We had a hard climb to this grotto, but it will be much easier going down." Hardly had Martine spoken when Priscilla, who was a few steps ahead of her, turned back with a cry of alarm. "Look, Martine; what shall we do?" Stepping up beside her friend, Martine too exclaimed in surprise. "Do you suppose it will come any higher? I have heard of the rapid rise of the tide, but this has just rushed in." Even in that first quick glance both girls realized that they were in a critical position. In going up to the "grotto," as Martine called it, they had taken no notice of tide-water marks, such as both of them might have observed. The rocky arms by which they had ascended were now covered by water, and an incoming wave dashed over Priscilla's feet as they stood there, uncertain what to do. "Will it come all the way in? We shall be drenched if it does." "No," said Martine, turning about and inspecting the nook where they had been standing when they heard Mr. Knight's voice. "You can see that if the last high tide had come in lately as far as that little hollow, there would be some water there now. Instead, it is perfectly dry. You can prove that for yourself." "Yes, yes, you are right; by standing back here we can at least keep dry, but oh, dear, when shall we get out?" "Probably not until Mr. Knight rescues us," replied Martine, cheerfully, "and even he will hardly come to our relief until low tide, which is probably some hours away." Whatever the real danger, Priscilla and Martine saw at once that they were in a very disagreeable predicament. The little niche in which alone they could have a dry footing on three sides had steep walls, whose height at the lowest was surely twenty feet. Martine scanned the sides carefully, but the stone surface was perfectly smooth. Nowhere was there a projection that offered the least foothold. It was in no way possible for either girl to climb to the top. Toward them flowed the advancing tide. It had entirely cut them off from the path by which they had reached the grotto, and though it might not be dangerously deep at every point of the beach and rocks that it now covered, neither girl had courage to venture into the water. Martine indeed had proposed to wade as far as it seemed safe, and then, if necessary, swim to some point where she might get a footing.