This is the 18668th most frequent Korean word.
신비
"신비" means "mystery" or "mystique" in English.
Here, "신비" is used as a noun to describe an abstract quality of mysteriousness filling the place.
이 장소는 신비로 가득 차 있어요.
This place is full of mystery.
In this sentence, "신비한" is an adjective form derived from "신비" and describes the atmosphere as possessing mystery.
그녀의 예술 작품에서 신비한 분위기가 느껴져요.
Her artwork evokes a mysterious atmosphere.
The phrase "이 신비" uses "신비" as a direct object referring to a specific mysterious matter being resolved.