The time: April 3rd, 1968. Martin Luther King (played by Samuel Jackson) is alone in room 306 in The Lorraine Motel in Memphis a day after he made his prophetic "I've been to the Mountaintop" speech, the day before he is assassinated. We see him as his private self -- using the toilet, wanting smokes, smelling the reek of his sweat when he takes his shoes off.
In comes the maid, Camae (played by Angela Bassett). The playwright, Katori Hall, really did her job of creating perfect character arcs. The maid begins nervous and reverential around King, then ends up so bold that she slips his jacket on to critique his preaching style and shows him how he should sound. And Katori's Martin Luther King goes from the all too human man who frets about whether his mustache makes him look old, a man who needs a woman's body next to his, never mind it isn't Coretta's. In the mesmerizing verbal parry between Martin Luther King and Camae, Katori Hall brings him and the audience right up to the mountaintop.
It has a supernatural element too which I don't want to give away.
See it at the Bernard B. Jacobs Theater, 242 E. 45th St. (Between Broadway and 8th.)