His heart sank.

They were going to have a feast or an orgie on the beach and the day would be sure to find them there.

Then they might conclude to explore the island, or at least far enough to find his house.
They dragged up wood, lighted a fire, warmed their food and ate and drank, talking much, and now and then singing wild songs.

Robert knew with absolute certainty that this was another pirate ship, a rover of the Gulf or the Caribbean, hiding among the islands and preying upon anything not strong enough to resist her.
The men filled him with horror and loathing.

The light of the flames fell on their faces and heightened the evil in them, if that were possible.