Olney Theatre traditionally opens the summer season with a thriller, often one as musty as the evocative aroma of the playhouse. This year the choice is "Deathtrap," a work of fairly recent vintage (1978) but one that threatens to become this country's "Mousetrap," a play that never dies, though most of the characters do.

Once you've seen "Deathtrap," and I suspect much of the English-speaking world has, you fall into one of two camps: those who enjoy revisiting familiar terrain, not quite remembering who jumps out and scares you when; and those who find on repeated viewings the exposition tedious and the gimmicks contrived. For the first camp, Olney's competent but uninspired production will provide a nostalgic evening. The second will wish the entire company would retire to the unseen garden patch in which one character spends part of the first act preparing for his victim.

In many ways "Deathtrap" is like the monster who remains impervious to every assault, deflecting daggers and bullets and bombs only to continue its deadly advance. It cannot be deflated by undistinguished performances; neither, I suspect, can it be elevated very far by brilliant ones.

Thrillers are, as author Ira Levin has his aspiring playwright say, "a superbly challenging theatrical tradition." The challenges are those of skill and craft, rather than brilliance or art, but Levin is an expert at meeting them. The surprises are there, as well as the suspense, and the essential tricks to fool the audience into thinking they have figured it all out.

Levin also employs a self-parodying device -- the plot revolves around a playwright who writes thrillers who has been sent a play called "Deathtrap" by a former student. As the student later starts writing a play about exactly what occurred in the first act, the action on stage and the characters' commentary on it become inextricably entwined in a dense web. This device wears thin after a while, particularly at the ending, which seems slapdash and farcical.

The cast is proficient but underrehearsed.

Stephen Joyce is the devious playwright, and in his hands the man is charmless. As the erstwhile student, Michael Alan Gregory has good looks but a very light voice, and Irwin Ziff's lawyer is characterized by a pair of overactive eyebrows.

Vivienne Shub plays the eccentric psychic with predictable dramatic zeal.

Lewis Folden's set evokes neither the historic New England cottage it is supposed to be nor the wealth its owners are supposed to have, but rather a tract house with imitation wood paneling.

The "antiques" are patently not, although the weapons displayed on the wall look extremely authentic.

"Deathtrap" can still produce a few genuine screams, and at Tuesday's opening the thunderstorm outdoors dovetailed eerily well with the rain from which the characters on stage were scurrying.

Unfortunately such atmospheric special effects cannot be ordered up on demand.

Deathtrap, by Ira Levin. Directed by Charley Lange, set by Lewis Folden, costumes by Patrick Wiley, lighting by James D. Waring. With Stephen Joyce, Aideen O'Kelly, Michael Alan Gregory, Vivienne Shub and Irwin Ziff. At the Olney Theatre through June 15.