He had never seen a cactus before; his stomach was like water to think of all the unknown perils about him.

Regis added quickly, giving the impression that he was trying not to emphasize this unknown peril.

Yet he was obviously anxious that I should escape some unknown peril.

It's also true that the story isn't over, that unknown perils - another attack?

You and I must stand beside Father in this unknown peril.

And perils known and unknown will grow as we go on.

Had Blue Hawk, too, fallen victim to the unknown peril?

Darkness and the unknown perils that awaited them below added to the fears.

Louis Wu, cool as a computer while his woman faced unknown peril.

And certainly unknown perils were waiting for them, not only at their destination but in the transporting itself.