It's reassuring to know that the message of a timeless play can shine through a so-so production. ''The Crucible'' is like that. Although not Arthur Miller's best, the play about the hysteria leading up to the Salem witch trials (with overtones of the McCarthy hearings of the '50s) is a never-dated red alert to the dangers of group-think and of relinquishing one's own conscience. And the power of that message can blast through even a tepid production.
The production by the Open Door Theatre (held outdoors in Jamaica Plain) suffers from lack of definition. In the program notes, director Ursula Drabik writes that ''This community could exist in rural Salem in 1692 or 50 years after the first nuclear winter thaw.''
True, but divorcing a play from its anchoring circumstances usually robs it of its logical urgency - especially if a clear set of new circumstances isn't provided. And that is largely what happens here. There's no reference point in the sparse furniture, and the costumes span the centuries in style and color. With the exceptions of Larry Blamire and Cynthia Woods as the Proctors and Anne Dayton as Abigail (who are fine), the acting is too tame to carry the powerful story.
So I wasn't bowled over by the production - but something kept me interested. It was Miller's clarion call to us for our vigilance against the real demons of the world: hypocrisy, bigotry, hatred, and ecclesiastical pride. Through Sept. 29.