Call it Thriller Karaoke, a form in which the story is almost as dangerous as the mode of storytelling. You worry that O'Connell will fall out of sync with the recording, which never stops once the play begins. Gradually, though, as her inerrancy becomes clear, you let go of that concern and switch to related ones: Why tell the story this way in the first place? What do you get from the astonishing feat, besides astonishment, that you wouldn't get if the same material had been acted out as it might be in a typically effective television procedural?