Sometimes, just sometimes, I enter the world of a play so thoroughly that I resent the break of the interval. Tom Stoppard's Hapgood at the Jungle Theater took me deep inside Cold War espionage in Britain, a world of "honey traps," "bleeps" and of triple and quadruple-turned "Joes." The Jungle's excellent production of Stoppard's spy thriller revels in rich language, strong characters, uncertain love and, would you believe it, particle physics! The unpredictable and binary nature of particle physics becomes a metaphor for the tricky action of Stoppard's witty and cultured Hapgood.

As the only female agent in Blair's unit at British Intelligence, the attractive Elizabeth Hapgood runs a Russian joe, Kerner, a physicist now working in England, whom she personally recruited and "turned." Ridley is another of her joes, a clever and volatile man, and sex buzzes beneath the action of this play, like an elusive mosquito.

So bright is Hapgood that she stands tall among her male colleagues, plays chess without a board, and plays her joes in high risk moves on the changeable board of counterespionage. But there's an unknown mole in the unit, a mole who must be identified and smoked out.

Director and set designer Bain Boehlke creates an air of mystery and unpredictability in the sheer legerdemain of his opening set. Great granite-like blocks rotate to become a tiled Victorian men's changing room in a municipal pool. Here, in silence, a complicated series of "drops" takes place. Men appear, slide brief cases under closed dressing room doors, shift towels that are hung out like signals, pick up brief cases and leave. The drop has been made, but was it the planned "chickenfeed" fed to the Russians to keep them playing along, or was hard information on particle physics substituted?

Charity Jones, who has been taking a respite from the stage, belongs in the role of Hapgood as naturally as the lungs belong in the chest. She exudes an understated sexuality and nails Hapgood's wit and hard-edged competence; yet she also finds her character's vulnerabilities as a single mother and a woman in love. All this in a nearly flawless English accent.

In Phil Kilbourne, director Boehlke has found a matching star to play Kerner, the erudite Russian physicist. Kilbourne infuses Kerner with such quiet charisma that even when he's pontificating about particle physics I was hooked, and his English-by-way-of-Russia accent holds throughout. We should be seeing much more of both these actors in the Twin Cities.

Also strong are Alex Podulke as the taut Ridley, Michael Tezla as the avuncular Blair, and Shawn Hamilton as Wates, the CIA man sent to help winkle out the mole. Wade Vaughn radiates a campy sweetness as Hapgood's secretary and, as her child, Matthew Morrison glows with the polite wholesomeness of an English schoolboy.

Under Boehlke's direction in this ambitious production the elements of theater fuse to create both the murk and the humanity of Hapgood's complex world. Scott Edward's sound design brings to the stage the drone of airplanes en route to Heathrowe, the opening and closing sounds of a door that physically does not exist but that feels concretely present; and the echoey sound of voices in the shooting gallery makes the space seem cavernous.

Also essential to conjuring the shadowy world of Cold War British espionage is Barry Browning's adroit light design. His lighting conjures mood and throws different textures upon Boehlke's adaptable set elements and helps them transform into five different scenes.

As the play progresses, the tensions mount towards a climax that I defy anyone to guess in advance. When it was all over, we couldn't stop taking about the legion subtleties that pack this Hapgood with such oomph.

Hapgood continues through November 3 at the Jungle Theater, 2951, Lyndale Ave. Minneapolis. Call: 612 822-7063.

Be sure to check the current schedule for theatre in the Twin Cities area

- Elizabeth Weir