At 89, Peter Brook, whose Midsummer shocked audiences back in 1970, is still producing interesting work.  The Valley of Astonishment, co-written and co-directed with Marie-Hélène Estienne, follows three people who lead unusual lives of the mind: the first, Sammy Costas (Kathryn Hunter), has a nearly perfect memory and unconsciously uses techniques similar to those outlined in Joshua Foer’s Moonwalking with Einstein.  Jared McNeill plays a synthesthete whose ability to see music allows him to paint John Coltrane.  And Marcello Magni is a man whose inability to sense his body forces him to use his brain to overcome paralysis.  At the center are the doctors who study these three (played alternately by Ms. Hunter, Mr. McNeill, and Mr. Magni), who act as our surrogates as they try but fail to understand these phenomena.  But Valley of Astonishment spends most of its time with Sammy, who is fired from her job at a newspaper (she is deemed overqualified) and becomes a variety act until she finds she that her capacity for storage is reaching its limit.  “How do I forget?” she asks in one of the play’s more poignant moments.

Still, like their last piece to visit New York, The Suit, Mr. Brook and Ms. Estienne’s Valley of Astonishment feels thin.  The material is rich, the opportunities for philosophical meditation abundant, but at 90 minutes, nothing is ever investigated sufficiently.  There is a scene, for example, in which Mr. Magni plays a one-handed magician who performs before Sammy.  He invites reluctant members of the audience onstage and does a few neat tricks, and it is sort of odd and entertaining to see such a shticky interlude right in the middle of a rather high-minded play, but it contributes nothing to the whole and takes up far too much time.

In fact, were it not for Ms. Hunter, I doubt The Valley of Astonishment would be worth much at all.  Surely one of the best living stage actors, she is thoroughly convincing as Sammy, her craggy voice at times poetic and at times heartbreaking—it is the voice of a female Samuel Beckett—and her slightly askew figure nicely accents her mental alienation.  Mr. McNeill and Mr. Magni are also quite good, though their peripheral roles do not offer much of a chance to see their talent.  Ultimately, The Valley of Astonishment raises problems it does not allow itself to even partially answer, leaving us teased and unfulfilled.

The Valley of Astonishment runs through October 5th at the Polonsky Shakespeare Center.  262 Ashland Place  Brooklyn, NY.  1 hour 30 minutes.  No intermission.