Already much of the machine was lost in sullen, lightning-charged clouds.

Just sullen clouds stacked up over the giant peaks.

He glanced out the window, to where the sun had almost set in a welter of sullen purple clouds.

The room was at the top of the house, at the back, and one saw nothing but sullen clouds.

My eyes swept the coastline, green and lovely even under the sullen clouds.

A sullen little cloud of steam rose from its pale greenish surface.

Like a sullen black cloud, their lust joined with the lightning of their hate.

Overhead, wisps trailing from the sullen clouds drifted by, almost close enough to reach up and touch.

Her eye did not see the sullen cloud which still rested on the brow of her beloved.

To one side there was a large pool, reflecting the sullen clouds.