What is the main conflict in The Secret Rapture by David Hare?

In an article he wrote for the Listener just before The Secret Rapture opened in London in October 1988, David Hare revealed the source of the play's curious title. "In Catholic theology," the playwright explained, "the 'secret rapture' is the moment when the nun will become the bride of Christ: so it means death, or love of death, or death under life." True to its origins, the play is filled with images of death, from the opening scene, in which a young woman keeps a vigil over the body of her dead father, to the climax, in which that same young woman is murdered by her obsessed lover. In between is a family drama rich with the symbolism and topical social criticism for which Hare has become well known in more than three decades as one of Britain's most popular playwrights.