By Barbara Trainin Blank
For The Patriot-News

That the human heart is the greatest mystery is demonstrated by John Pielmeier's compelling three-character play, "Agnes of God."

At its heart is an actual mystery: A psychiatrist, entrenched in the scientific method, is asked to evaluate the fitness for trial of a young nun who might have strangled her baby. And whose pregnancy is one of the play's mysteries.

That mystery is wrapped in psychological drama: Who will prevail in the clash of wills -- the miracle-rejecting psychiatrist, or the protective Mother Superior who hopes for at least one.

Will it be Agnes, the troubled "innocent" who might have been blessed by God?

Tangentially, the play also explores the nature of sanity, since each of these women possesses her own demons.

To say that the role of Agnes is challenging for a young actress is an understatement. Amy Burke, who has played strong women onstage so effectively, is particularly fine here whenever the flood of emotions overcomes the troubled nun. Her descent into hysteria seems natural and her decomposition most affecting.

Yet, in the "lighter" early moments, Burke's Agnes seems more simple-minded than simple -- making it harder to understand why she would inspire such love.

Andrea Catlin, who portrayed Dr. Livingstone in Theatre Harrisburg's 1985 production, offers a human Mother Superior in a performance that debunks the more saintly, dignified depictions often seen in similar characters in the movies. There are times that her throaty voice and down-to-earth approach almost verge on the coarse, but they also enhance her delivery of the play's comic lines.

Carrying the weight of the drama is Constance Kuba Fisher in the pivotal role of the psychiatrist. Kuba Fisher, who played Agnes in the earlier production, is a bit too intense in the first act monologues but relaxes in the second.

In the scenes shared with the other actresses, she is consistently eloquent -- whether speaking or silent. Kuba Fisher captures the character's outwardly cynical side and the inward vulnerability of a woman bruised by life.

The dramatic tension between the two women battling for Agnes' soul and her physical freedom is effectively done, never overdone, by the two performers.

"Agnes of God" might seem a bit melodramatic or contrived at points. It also has become "dated" somewhat since its 1979 writing (most psychiatrists today don't do therapy in the way they once did).

But the underlying issues of faith and love are universal and timeless.