Back on the ocean, a fresh wind blows from the west and speeds the voyagers toward home. Ulysses hopes good weather will help them sail past the dangers they’ve been warned about. Maybe the ghosts, given their gloomy nature, were too pessimistic about his prospects.

Hardly has this thought arisen when he hears a grinding, moaning sound in the distance. Climbing the mast, he spies floating rocks moving toward them, chafing against each other. He orders the ship to come about and escape, but the rocks pursue. Ulysses takes the helm and circles around to let the rocks pass, but they follow him. The rocks keep their distance but block his path to the south; when he steers that way, they stand fast, looming and threatening.

Ulysses realizes the rocks are meant to block his way past the dangers foretold by the ghosts. He gives up and sets course for Sicily and the Sun-Titan’s dangerously tempting cattle.

The ship must pass through a strait guarded by the island of the Siren sisters, two sea witches whose song lures sailors to their deaths. As captain, Ulysses must retain his hearing, so he plugs his men’s ears with wax and has them tie him tightly to the ship’s mast.