Duress

There's a trope in detective stories, I guess, where the young woman escapes a murder attempt, then somehow ends up in the same room with the guy who tried to murder her, who still wants to do it but for some reason can't do it immediately, so attempts to calm his prospective victim, and keep her from fleeing or causing a stir, by convincing her he is there to protect her, which she knows is a lie but plays along because to reveal her knowledge that she knows he tried to murder her would result in an immediate re-attempt.

And then there's the story of Yulia Skripal:  "Yulia Skripal Is Plainly Under Duress" (Murray).