I saw the movie version (made for television, despite its absolute perfection) not long after I read the Edson's play. I've watched the movie version so many times, the actual play and movie have merged a bit in my memory.
There is no way to "spoil" the plot, given that we learn Vivian Bearing, a John Donne scholar of distinction, tells us she is dying at the outset. Bearing's entire life has been one of the mind. Her terminal cancer forces her to confront the mind/body split in a particularly compressed and poignant fashion. Repeatedly, she refers to herself in terms of her work - her mind - even when she is being subjected to tests or vomiting from the chemotherapy. Her slow movement toward attending to her body and reaching out to other human beings make for a compelling transformation. And, for lovers of John Donne, there are meaty allusions to his works, and you will never read his sonnet, "Death Be Not Proud," the same way again.
The movie - which has few variations from the play - is mesmerizing. Emma Thompson is luminous, human, intelligent, and drolly funny as Vivian Bearing, and while the movie/play is strangely uplifting, I cry - predictably - every time I watch it. Both the play and movie are among my favorites.