Lee Blessing's new play revolves around a simple but ingenious premise: a middle-aged man and woman wake up in bed together in a well-appointed house, surrounded by water, with no idea who they are or how they got there. A young woman's entrance deepens the mystery after she alternately identifies herself as a lawyer trying to crack a murder case and as their daughter. Edward Herrmann and Michael Learned play the couple with depth and skill, particularly when navigating the question of what their relationship might have been in their pre-amnesia life. Similar kudos are due designer Michael Sims's set, which is simple and elegant and contributes to the impression of the players being isolated in an aerie of forgetfulness. Adding to the visual pleasure of the show is Matthew Reinert's lighting, which marks the passing of time by reflecting the changing of the seasons (and, in a subtle touch, the undulating of the waves outside). Michelle O'Neill as Wren, the attorney/daughter, makes her character's entrance shocking with an air of breezy disapproval, and captures the sorrow of her reality when the play's ultimate secret is unpacked. I was less illuminated by what came between, though, because I felt I was looking in her performance for clues that weren't being provided--her exasperation and condescending irritation with the older couple provided an intriguing note, but the wait for added dimension was a bit too long. That said, director Ethan McSweeny has put together a genuinely disturbing and affecting take on a work that starts out as an allegory on the wispiness of identity and eventually transforms itself into a very specific story about a single individual. Blessing has trimmed down earlier drafts of the work into a tight 90-minute show, for which audiences can be grateful. This is strong stuff, and the limitations of its setup mean that the ship starts to drift about halfway into the evening. The show rallies, though. By the time the curtain falls, the audience is stunned by the way things have gone. It turns out we have witnessed a show about a personal hell from which there is no escape.