ˈTwilight ˌZone, the
a US television programme, originally made between 1959 and 1963, and then again in the 1980s, with a different story and characters each week. At the start of each programme a voice says ‘You are now entering the Twilight Zone’ and the stories usually deal with supernatural events or science fiction.

[TahlilGaran] Dictionary of Contemporary English ▲

twilight zone
the area where one thing ends and another begins, especially when it is not clear exactly where or when this happens.
She'd been unconscious ever since she fell, trapped in the twilight zone between life and death.
(often + between)

[TahlilGaran] English Idioms Dictionary ▲