Unless, indeed, the electricity was drawn directly from the surrounding air or from the water, by processes hitherto unknown.

Perhaps, by some unknown biological process, they were.

Under these conditions, the currently unknown processes should occur.

"And there is a fear of the unknown about what will come out from this claims process."

Could some previously unknown atmospheric process be at work?

Perhaps it was true sunlight beamed through some unknown process of Ruhkarv's builders into this hollow.

Some unknown physical process at the surface of the red giant, perhaps?

We are involved in processes unknown two years ago.

When cooled, the diffuse material in the medium forms clumps that scientists believe evolve into stars through a largely unknown process.

We'll look like just one more planet afflicted by this unknown process.