An eerie feeling of deja vu might creep over you while watching Tennessee Williams's rarely staged "Portrait of a Madonna," on view at Gunston Arts Center in a double bill with the Williams one-act "Suddenly Last Summer." This aging, sex-obsessed Southern belle who's drifting into madness, clinging desperately to her genteel illusions and acknowledging the kindness of strangers -- is she not Blanche DuBois?

"Portrait," a poignant half-hour vignette first staged in 1944, is very much a dry run for the final scene in "A Streetcar Named Desire" -- right down to the sympathetic doctor and hard-boiled nurse who ultimately arrive to cart the lady off to the loony bin. Diffuse and underdeveloped, the sketch falls miles short of "Streetcar's" tragic grandeur, but it can be mildly interesting to spot the familiar motifs in the tale of Lucretia Collins, an unhinged spinster whose erotic hallucinations prove to be her undoing.

Under the direction of Leslie A. Kobylinski, the Keegan Theatre has cobbled together a workmanlike production of "Portrait," never elevating it past the level of a literary curiosity (although the theater-in-the-round staging somewhat ratchets up the emotional voltage).

Sheri S. Herren gives a rather numbed interpretation of Lucretia, a character whose deranged monologues ramble through coquetry and paranoia, through prissy statements about the Episcopal Church and tangled memories of a former lover. Drifting across the stage in a blue dressing gown, her feet bare and blond hair matted, Herren conveys a well-bred bewilderment but she doesn't fully inhabit Lucretia's insanity, physically or vocally. You get a better sense of the lady's nuttiness from Grant Kevin Lane's set -- gray sheets draped over the furniture; books, papers, and elements of a tea service strewn across the floor.

Scott Graham smirks adequately as the nosy Elevator Boy in Lucretia's building, but Timothy Hayes Lynch brings more compelling intensity to the role of the Porter. Staring broodingly about him, hands plunged in the pockets of his blue boiler suit, Lynch exudes a gruff compassion that sharpens the play's melancholy tone, particularly at the end, when he's captured in a wistful fading-light effect.

Not surprisingly, given its superior script, the more watchable half of the Keegan bill is "Suddenly Last Summer," the creepy study of a New Orleans family racked by jealousy, greed and a sexual secret. This play, which premiered in 1958, features a woman in a state of non compos mentis: the gutsy Catharine, whose revelations about her dead cousin Sebastian infuriate Sebastian's mother, Violet Venable.

Marybeth Fritzky does a splendid job as Catharine. The restless darting of her eyes, the twitching of her clenched fists, the jerky way she moves her head -- all her body language suggests borderline psychosis, but she seems vulnerable, too.

Also notable is Graham as the courteous Dr. Cukrowicz, who's suitably troubled by Mrs. Venable's insistence that Catharine needs a lobotomy. Herren makes an unnervingly serene Mrs. Venable, and Kathryn Fuller and Mike Sherman are convincingly uncouth as Catharine's mother and brother.

All the characterizations benefit from Lane's aptly chosen costumes, including a gorgeous lavender silk dress for the snobbish Mrs. Venable and an ugly green suit, paired with yellow gloves, for Catharine's mother.

With its dead leaves and empty plant pots, Lane's set for "Suddenly" is perhaps not quite the menacing Gothic garden that Williams intended -- although four green hanging shutters threaded with leaves do hint at natural lushness, as does the bird-song by sound designer Keith Bell.

What makes this production most effective, though -- other than Fritzky's performance -- is the cast's focus and coordination as an ensemble. When everyone's onstage, as the melodramatic moments flow, you can sense the characters' conflicting self-interests hanging ominously in the sultry New Orleans air.

Portrait of a Madonna and Suddenly Last Summer, by Tennessee Williams. Directed by Leslie A. Kobylinski; lighting, Franklin C. Coleman. Approximately 2 hours 15 minutes. Through Dec. 17 at Gunston Arts Center Theater II, 2700 S. Lang St., Arlington. Call 703-527-6000 or visit www.keegantheatre.com.

Sheri S. Herren as Lucretia Collins and Timothy Hayes Lynch as the building porter in "Portrait of a Madonna."A troubled Catharine (Marybeth Fritzky) and Dr. Cukrowicz (Scott Graham) in "Suddenly Last Summer."