Outside, the storm still raged off the mountain, bringing with it an impenetrable curtain of snow.

By eight o'clock the clear skies that had for so long looked down on the President Arthur were lost behind an impenetrable curtain.

Far out, over the southern ocean, the last remnants of the afternoon's thunderstorm hung against the horizon like a black and impenetrable curtain.

Behind loomed the forest, rising like a massive, impenetrable curtain.

The wind did not slacken, the snow fell in an impenetrable curtain; and the cold, already bitter, grew even more intense.

A double curve in the huge river had appeared last and it disappeared first as the impenetrable curtain of semispace started to close once more.

"Incredible that a project so vast could be carried off behind an impenetrable curtain of security, unknown and undiscovered for twenty-six years."

The trees loomed in front of her, an impenetrable black curtain.

The smoke from the three tiny bombs merged in an impenetrable curtain.

There was nothing to be seen except the white swirling mist, an impenetrable curtain.