And, as they watched, it crept quickly along the blue-enamelled plain. It swallowed up the southern cliffs of Guernsey. Its creeping nose was level with the tall Doyle column. It crept on and on, till Castle Cornet disappeared and Peter Port was lost to sight. On and on—Jethou was gone, and bit by bit the long green and gold slopes of Herm were conquered, and its long white spear of sand ran out of the low white cloud. And still on, till all the outlying rocks and islands vanished, and where had been the glow and colour of life was nothing now but that strange pall-like cloud.
The blue of the sea in front had whitened, and suddenly the sentinel rocks at the tail of Brecqhou disappeared, and the white cloud came sweeping towards the watchers on the rock by Tintageu.
"We're in for it too," said Graeme, hastily emptying his kettle and packing up the tea-things. "Seems to me we'd better get ashore."
But the cloud was on them, soft films of gauzy mist with the sun still bright overhead. Then quickly-rolling folds of dense white cloud blotted out everything but the path on which they stood. The gorse and blue-bells and sea-pinks at their feet drooped suddenly wan and colourless, as though stricken with mortal sickness, and wept sad tears. They stood bewildered, while the pallid folds grew thicker and thicker, lit from above with a strange spectral glare, and coiling about them like the trailing garments of an army of ghosts. From the unseen abysses all round came the growl and wash of wave on rock and shingle, from the cliff above Pegane came the frightened bleat of a lamb, and an invisible gull went squawking over their heads on his way inland.
With an instinct for safer quarters, Miss Penny had started off towards the path which led precariously across the narrow neck to the mainland. The neck itself, with white clouds of mist billowing on either side, and streaming raggedly across the path, looked fearsome enough. She gave a startled cry and stood still.
"Stay here!" said Graeme to Margaret. "Don't move an inch!" and he felt his way, foot by foot, towards the causeway.
And Margaret, who had been regarding it all simply as a curious experience, felt suddenly very lonely and not very safe.
She heard him speak to Miss Penny, but she could not see two feet in front of her.
Then, after what seemed a long time, she heard above her—
"Miss Brandt? Margaret? Oh, good God!"—and there was in his voice a note that was new to her. Sharp and strident with keenest anxiety, it set a sudden fire in her heart, for it was for her.