This article is dedicated to revealing linguistic means that realise "the event" in the gothic narrative--H. James's novella "The Turn of the Screw" and the opera libretto of the same name. The event is treated as a situational change of states and presupposes that "the real" and "the unknown" should meet. This meeting runs through the whole narrative. "The event" is ideal and abstract; it shows itself in concrete manifestations--incidents. Discerning "the event" is possible by analysing linguistic signals of its manifestations--"traces". In both the novella and libretto (though varying in structural peculiarities of "the event") the most vivid and noticeable trace is expressed by such a neutral word as "bad"; every appearance of this word in both texts "turns the screw" tighter; it is a common keyword sustaining the original story flavour. As a linguistic sign the word "bad" is analysed from perspectives of different characters.