The sea had changed. It was dark green now with white-horses, and the rocks shone yellow like phosphorus. Rumbling solemnly, the thunderstorm came up from the south. It spread its black sails over the sea; it spread over half the sky and the lightning flashes with an ominous glint. “It’s coming right over the island,” thought Snufkin with a thrill of joy and excitement. He imagined he was sailing high up over the clouds, and perhaps shooting out to sea on a hissing flash of lightning. Now the sun was gone, and the rain was driving like a grey curtain over the sea. Though it was still many hours til evening the whole world was shrouded in darkness.