black curtain
wirepuller; mastermind; backroom manipulator; éminence grise; power broker
事件の黒幕はまだ不明だ。
The mastermind behind the incident is still unknown.
政界の黒幕と呼ばれていた。
He was called the power behind the political world.
黒幕の存在が暴かれた。
The existence of the mastermind was exposed.