Today's magic word is "synesthesia," a rare brain condition in which someone's senses blend together, knocking into each other and creating unexpected and powerful visions and abilities. For instance, a person could see colors upon hearing sounds and vice versa.

It is the subject and source of inspiration for "The Valley of Astonishment," an uneven but inspired new work by the 89-year-old director Peter Brook and Marie-Hélène Estienne, which is receiving a short run at Theatre for a New Audience in Brooklyn.

Brook is a theater legend, having written the seminal theory book "The Empty Space" and directed numerous productions including the avant-garde "Marat/Sade," a groundbreaking experimental production of "A Midsummer Night's Dream" and the "The Mahabharata."

In recent years, Brook has presented extremely lean and intimate productions, with few actors and little scenery, which go on to tour the world. "The Valley of Astonishment" falls into that category.

The 80-minute piece explores various individuals who display signs of synesthesia, most especially a middle-aged woman (played by the wonderfully expressive Kathryn Hunter) who has an extraordinary ability to memorize long passages of words and numbers by instantly converting them into images in her head. Once her talent is discovery, she becomes a curiosity for neurologists and a vaudeville attraction.

It's too bad the play can't just be about her. Instead, it constantly veers off-track. At its worst, 15 minutes are consumed by a one-handed magician playing card tricks with volunteers from the audience.

But at its best, "The Valley of Astonishment" proves to be a very compelling and distinctive work, offering digestible and sympathetic insight into a strange, special condition. Its meditative quality is heightened by having two onstage musicians, who build upon the text atmospherically.

If you go:

2.5 stars

‘The Valley of Astonishment’ plays at Theatre for a New Audience through Oct. 5, 262 Ashland Place, tfana.org.