Several hours after the final bows for David Mamet’s tense, hour-long 1994 drama, my stomach is beginning to unclench. Kelly Kitchens directs the obsessive piece, set in 1959, about nervous young John (11-year-old Rowan Calvert), his jilted mom Donny (Emily Grogan), and their family friend Del (Richard Nguyen Sloniker). Without blows, cursing, drugs, or sex, The Cryptogram dispenses a sly nerve toxin—no small accomplishment in these desensitized times. Yet it’s a hard play to admire, because the noxious tension is born of bait-and-switch. Mamet’s hinted-at prospect of a chewy thriller crumbles into a postmodern vignette about failed communication and emotional frostbite.

John can’t shut off his churning mind or accept easy answers from adults. Scheduled to go camping the next day with his dad (who never shows up), John’s insomnia, OCD-like ruminations, and interrogations are driving Donny and Del to distraction. They speak classic, halting Mamet-ese, minus the f-bombs but full of unhearing “What?”s, fragmentary ellipses, and stilted pronouncements. (Del says of the absent father’s knife, “It’s a propitiation for the boy.”) The tone and intentions seem muddled, which ratchets up our discomfort for only short-term gains. Is Del—who seems the most sympathetic to John’s vulnerable sensibilities—a nice guy or a slimeball? Is Donny always an ice queen on the brink, or is she just victim of bad circumstances?

Grogan and Sloniker, who together evoked so much empathy in Book-It’s The Cider House Rules, here seem encapsulated by Mamet’s mean vision. In heart-sickening fashion, the adults’ personal preoccupations blind them to the eccentric, haunted, and urgently attention-seeking John. As with glimpsing the details of any child abuse/neglect case, there’s a sense of filth and failure as we leave the theater. Final score: Mamet 1, us 0.