All the time, they were an unknown world to each other.

He's been gone some weeks, lost in an unknown world.

How, after all, do you train to face a completely unknown world?

Nor do we wake at each moment into a new, unknown world.

I took my ship to an unknown world instead of setting course for home.

But weak as Gordon felt, he couldn't without first looking out at this unknown world of the far future.

Every dive was a new adventure through an unknown world.

He felt rather helpless, practically alone in this unknown world.

She is neither the first nor the last to claim a heritage in an unknown world.

Their count was off, however, and the two men were suddenly in the humid air of the unknown world.