The Barter Theater production of "Deathtrap" at George Mason University in Fairfax shows that America's oldest professional theater company is as lively and vital as when its players worked for real peanuts.

Ira Levin's splendid thriller-comedy requires flawless timing and intricate stage business, but Barter has brought it off with never a glitch. There isn't a flat spot anywhere in the evening, and Ross Bickell carries the endlessly demanding lead role with such exuberance that you wish there were a third act.

Barter's 50-year tradition keeps its company a family, and Bickell is solidly supported by Cleo Holliday, Edward Gero, Eunice Anderson and Craig Kuehl. It is not possible to describe what they do without giving away some of Levin's delightful plot twists, but it is hard to think how the material could be better served.

The setting by John C. Larrance gets a real workout, and it works; C.L. Hundley's costumes are so right that they don't seem to be costumes, and the lighting by Christopher H. Shaw makes the single set cheery and chilling by turns. Director John Olon's hand is everywhere in the production, but so deftly that it never shows.

And what a delight to be able to hear every word throughout an evening of theater.--.

DEATHTRAP -- At the Harris Theater, George Mason University, through December 20.