Resolving to hope he did hope.

He refused to believe that the slaver could make him vanish from the face of the earth like a mist before the wind.
The air in the little cabin was dense and heavy already, but after a while he felt it grow thicker and warmer.

He was conscious, too, of a certain sultriness in it.

The tokens were for a storm.

He thought with a leap of the heart of the earlier storm that had rescued him, but that was at sea; this, if it came, would be on a river, and so shrewd a captain as the slaver would not let himself be wrecked in the Hudson.
The heat and sultriness increased.