Playing a convincing nut is one of the biggest challenges facing an actor. Like being drunk onstage without falling over, the thespian wishing to personify madness in a persuasive way must avoid clichés such as clucking like a chicken or flinging wildflowers out into the audience (unless, of course, the stage directions specifically call for this kind of thing). The cast members of the Actors Theatre/OTM production of One Flew Over the Cuckoo's Nest understand this, and as a result, the white and green surfaces that surround them stop looking like bits of carefully constructed stage scenery and start resembling the forbidding walls of a state mental hospital. Dale Wasserman's play, based on Ken Kesey's 1962 novel of the same title (and subsequently developed into an Oscar-winning 1975 movie starring Jack Nicholson), tells the story of how Randle Patrick McMurphy, a convicted felon who contrives to get himself sent to a mental institution as a way of avoiding hard labor, impacts the lives of his fellow asylum inmates. Christian Phillips gives an explosive performance as McMurphy, but the true power of this engrossing production derives from the assorted catatonics, depressives, and other dysfunctional souls who litter the ward like bits of swirling trash. From Michael Speyser's lurking performance as Chief Bromden to Graham Cowley's physically daring personification of paranoid neurotic Cheswick, the characters are as convincing as they are tragic. The action is further intensified through the casting of Rachel Klyce as the authoritarian Nurse Ratched. It's easy to hate the hatchet-faced, big-chested woman of Kesey's novel and Milos Forman's film. But looking more like Kate Winslet and less like a matronly old boot, Klyce presents a savage sweetness that creates an even more disturbing dynamic on the ward.