Gradually their eyes, growing accustomed to the dim and changing light, could pierce the black line above the grey where the sea came stealing up the sandy places with low murmurs, throwing with every wave longer arms into the land.
"Twelve o'clock!" Collins muttered.
Suddenly Granet's fingers dug into his shoulder.

From out of that pall of velvet darkness which hung below the clouds, came for a single moment a vision of violet light.

It rose apparently from nowhere, it passed away into space.

It was visible barely for five seconds, then it had gone.

Granet spoke with a little sob.
"My God!" he murmured.