I stood, paralyzed in horror, while the shattered boat was driven full upon the great rock. I could imagine the crash of it, but it was all as still as a silent picture. The boat, riding high on a crest of white foam, smashed against the rock and was shivered to splinters. Virginia was hurled forward against the slick wet stone. Desperately she scrambled to reach the top of the boulder. Her hands slipped on the polished rock; the wild sea dragged at her. At last she got out of reach of the angry gray water, though spume still deluged her. I breathed a sigh of relief, though her position was still far from enviable. "Virginia! Virginia! Why did I let you go?" Charlie cried. Desperately he fell to work again, mounting the magnet and tubes. Another hour went by, while I watched the shivering girl on the rock. Bobbed hair, wet and glistening, was plastered close against her head, and her clothing was torn half off. She looked utterly exhausted; it seemed to take all her ebbing energy to cling to the rock against the force of the wind and the waves that dashed against her. She looked cold, blue and trembling. The water stood higher. "The tide is rising!" Charlie exclaimed. "It will cover the rock pretty soon. If I don't get her off in time--she's lost!" * * * * * He finished twisting his wires together. "I've got it all ready," he said. "Now, I've got to find out exactly where she is, to know how to set it. Even then it's fearfully uncertain. I hate to try it, but it's the only chance. "You can find out?" "Yes. From the spectral shift and other factors. I'll have to get some other apparatus." He ran up to the laboratory, across the level field that lay black beneath the stars. He came back, panting, with spectrometer, terrestrial globe, and other articles. "The tide is higher!" he cried as he looked through the blue-rimmed circle at the girl on the rock. "She'll be swept off before long!" He mounted the spectrometer and fell to work with a will, taking observations through the telescope, adjusting prisms and diffraction gratings, reading electrometers and other apparatus, and stopping to make intricate calculations. I helped him when I could, or stared through the ring of shining blue mist, where I could see the waves breaking higher about the exhausted girl who clung to the rock. Clouds of wind-whipped spray often hid her from sight. I knew that she would not have the strength to hold on much longer against the force of the rising sea. Although driven almost to distraction by the horror of her predicament, he worked with a cool, swift efficiency. Only the pale, anxiety-drawn expression on his face showed how great was the strain. He finished the last spectrometer observation, snatched out a pad and fell to figuring furiously. "Something queer here," he said presently, frowning. "A shift of the spectrum that I can't explain by distortion through three-dimensional space alone. I don't understand it."