"unknown fate" is correct and usable in written English.
This phrase is generally used to refer to an uncertain future or outcome of something. For example: "The crew of the ship was nervous as their unknown fate lay ahead of them."
Anxiety can be a talisman for an unknown fate.
A Druse gunman carried off the parrot to an unknown fate.
We now know that before their marriage, Einstein and his first wife, Mileva Maric, had an illegitimate daughter, named Lieserl, whom he abandoned to an unknown fate.
When it was invaded by the Daesh terrorist group in May 2015, I felt that life had stopped, that the ancient city was facing an unknown fate.
The shock of the loss showed on players' faces, but it was compounded by the unknown fate of so many of their teammates.
Once he has driven off to his new, unknown fate, a menacing trucker (Vincent Deniard) will supply all the danger we have dreaded and hoped for.
These morphological and genetic changes are consistent with the abolition of recombination, which precedes the genetic degeneration of neo-Y or neo-W chromosomes with unknown fates [ 1, 15- 21].
The bishops are among the thousands who have simply disappeared in this conflict, snatched by one side or the other, their whereabouts unknown, their fate uncertain.
Taken together, the results of this study suggest that QMSA could dramatically reduce the number of laboratory and field measurements required to characterize as-yet unknown environmental fate and behavior parameters for diverse emerging contaminants of regulatory interest.
You don't feel being saved from an unknown worse fate.
A native Indian, Waumanitt, was charged with the crime and held at Mowry's tavern until the matter could be resolved, but it is unknown what fate befell Waumanitt.
