"A yet UNKNOWN number
of robbers gained access...
Money Heist Season 1, Episode 6
somewhere UNKNOWN.
And most likely...
Money Heist Season 3, Episode 2
Unknown caller.
It's got to be them.
The Big Bang Theory Season 12, Episode 23
takes a bullet to the face
from a person or persons UNKNOWN.
Breaking Bad Season 4, Episode 7
...between the UNKNOWN...
Westworld Season 2, Episode 6