It is not of every theater group that one can say going will be a certain pleasure, but the Little Theatre of Alexandria does consistently good work.

Its current production is a thriller: "Wait Until Dark," first produced on Broadway in 1966 with Lee Remick and Robert Duvall. Playwright Frederick Knott was already established in the genre, with the great success of that snappy little masterpiece "Dial M for Murder" behind him.

Briefly, a little of the plot so as not to give anything away for thriller enthusiasts: a young bride, Suzy Hendrix, newly blind (therefore immediately engaging our concern and protective instincts) has been left at home alone for the day by her photographer husband.

Somewhere in the apartment is a doll, which is stuffed with a large amount of heroin. Her husband acquired this object by mistake, and a woman who claimed to own it made an urgent appointment to fetch it the night before. She never turned up. Coincidentally, a woman's body has been discovered nearby.

No sooner does the husband leave than three criminals arrive. They go through complex and preposterous scenes in which they all play nearly plausible characters in an effort to force Suzy to find and part with the doll.

Just on the point of doing so, she suddenly adds it all up, and sees through the criminal machinations. One of the criminals, masquerading as an old friend of her husband, has grown to like her -- so much so that he cannot bring himself to harm her. Unfortunately, he does not survive long enough to help her, as the most villainous of the three eliminates all of his competition.

True to its title, playwright Knott plunges the stage into darkness for his final scene, the villain thus also being rendered "blind." Only Suzy can find her way about. Or at least she stands an equal chance.

The final scene has all the qualities of the chase: near misses, violence, narrow escapes, much confusion, and a few breathtaking strokes of luck. The audience gasped and shrieked throughout this finale.

Much depends, as in all thrillers, on the power of the acting, which must carry the tortuous plot to this stunning denouement.

James McDaniel V makes a nice job of Mike Talman, the criminal who finds himself caring for Suzy. Stan Shulman makes jolly work of Carlino and provides great comic relief in a scene where he wipes virtually the entire stage clean of fingerprints.

Top honors in villainy go to Ken Allison as Roat, the mastermind who plays several assumed characters, and reveals himself cruel and vicious in the last scene. Allison has given several strong performances in the last couple of years, and is always an interesting actor to watch.

Madeline Mager as the little girl neighbor is right on the mark as a near-sinister brat in the early scenes, and proud friend to Suzy at the end.

Best of all, the production has as Suzy the talented Harriet Barrett, who is not capable of a bad performance. Here, she is at her most engaging. It is also a distinct pleasure to watch Barrett utterly eschew the cliche' wide-open glazed look for blindness, and give us an entirely new portrayal of Suzy's handicap. Revolutionary, one could say, and Barrett always makes us believe her.

Frank Ludwig's set is well planned, lighting designed by David Harris appropriately unnerving, and the whole is neatly directed by Ed Lockwood.

"Wait Until Dark," the Little Theatre of Alexandria through Feb. 2. For information, call 703-683-0496.