The trajectory of William Friedkin's career suggests that he may suffer from the paradoxical curse of early success. He directed two of the most important and influential films of the 1970s - "The French Connection," which transformed the cop movie, and "The Exorcist," which created an entirely new approach to horror - but since that time has never approached the level of quality or the wide appeal of those landmark works. Two of his more interesting films, among a parade of mediocrities, flopped miserably. His remake of "The Wages of Fear," foolishly titled "Sorcerer," pleased no one, and "Cruising," his daring thriller set in the dark world of sadomasochistic homosexuality, offended gravely against political correctness, thus losing the support of almost all the reviewers and perhaps permanently damaging his critical reputation.

In general, even in his weaker films, he seems entirely comfortable as a director in the traditional Hollywood mold, making big, highly polished action films with a contemporary sense of sex and violence, but despite the sensationalism, also permeated with a self-consciously 1940s melancholy and mannerism. His history of both success and failure, however, provides no convincing explanation for his newest production, "Bug," a small, intense, and essentially awful movie based on what must be an equally awful play, complete with all the usual problems inherent in the process of transforming theater into cinema.

Allowing only one brief shift of location, and now and then employing a slow overhead zoom from somewhere in the sky to the exterior of a squalid Oklahoma motel, the movie concentrates claustrophobically on one set, the rooms of Agnes White (Ashley Judd), a divorced waitress who insulates herself from loneliness and loss with booze and drugs. Her scant back story reveals that she mourns the disappearance of her 6-year-old son, missing now for 10 years, and that her ex-husband, Jerry Goss (Harry Connick, Jr.), just out of prison, blames her for the loss.

Another waitress brings a stranger named Peter Evans (Michael Shannon) over for a quiet evening snorting cocaine, smoking dope, and smashing down a few dozen shots, but the odd, soft-spoken fellow refuses to indulge; with nowhere else to go, however, he spends a chaste night sleeping on Agnes's couch. His calm courtesy and his desire to protect Agnes from Jerry softens some of her hostility and after a short while, the two become emotionally and physically intimate, which opens the central horror of the film. Peter notices some infinitesimally small bugs, which, he tells Agnes, the government inserted into his body in a series of medical experiments using soldiers as guinea pigs.

From that revelation the picture rapidly develops into a display of a kind of infectious paranoia, as Peter reveals a whole structure of deceit involving not only the microscopic bugs but also the government's elaborate chemical and technological methods of observing and controlling its citizens - the bugs represent both infection and eavesdropping. With the lucid logic of the lunatic, he demonstrates the connections between various military actions, the Tuskegee syphilis experiments, the Jonestown suicides, the attack at Waco, the Oklahoma City bombing, the Unabomber, and just about every other catastrophe of the last 50 years. His compelling arguments convince Agnes and she joins him in an astonishing and ultimately fatal folie a deux.

The intense inward focus of the movie, which essentially devolves into a two-person, single-set production, betrays its origins in a stage play, too often neutralizing the motion of the motion picture. No matter how sharply and steeply the nuttiness escalates, "Bug" remains enclosed in the suffocatingly narrow space of the motel room as surely as all the real action occurs within the crazy relationship of two highly unstable people.

The static constriction of subject and method contrasts sharply not only with the traditions of cinema, but also with the particular history of Friedkin's career. Even his failures usually exhibit some understanding of lively, entertaining filmmaking, an inclination to create something original and exciting within a number of the great standard Hollywood genres. Filming a really ridiculous stage play so literally that "Bug" practically lowers a curtain at the end of its three acts, however, indicates a drastic decline in the imagination of an accomplished and presumably talented director.

"Bug," (R) directed by William Friedkin, is now playing in area theaters.