I am, as I have been regularly reminded of late, a real sucker for repertory. There’s something about seeing actors in two or more plays in close succession that invariably catches me up short, making me hear a voice, or see a gesture, or note phrasing parallels and plot similarities that would likely escape me if I saw the shows a month apart, or in different theaters with different casts.

Even mere theater-sharing of the sort that’s been occurring lately at the Source Theatre—two companies occupying the same space on different nights—can create intriguing reverberations in unrelated evenings. Rotate six Sondheim musicals at the Kennedy Center for a whole summer, with directors approaching texts in entirely different ways but ending up with moments that harmonize and blend contrapuntally, and it’s hard not to come away with the sensation that rep is theatrical nirvana. (With any luck, the KenCen’s upcoming Tennessee Williams rep will offer similar revelations; after all, the shows on tap are familiar enough that there may well be as many patrons mouthing, “I have always depended on the kindness of strangers” as there were humming along to “Send in the Clowns.”)

Local troupes don’t tackle real rep much anymore. Back when it had an actual acting company, Arena Stage used to find an excuse to rotate several plays in one of its houses every couple of seasons, but that was decades ago. Luckily, though, the Shenandoah Shakespeare Express almost always brings a comedy, a history, and a tragedy for its annual visit to D.C. When an actor plays the title character in King Lear one night and the Duke in Much Ado About Nothing the next, it’s easy to see not just different Elizabethan takes on authority figures, but also how 17th-century acting companies must have functioned.

Even when half of a repertory proves disappointing, as is the case with “The Shepard Project,” the two Sam Shepard plays that the Keegan and Fountainhead Theatres are co-producing with near-identical casts at the Clark Street Playhouse, the fact of the rep itself can offer patrons compensatory pleasures. Keith Bridges’ soporific mounting of Sam Shepard’s Pulitzer-winning Buried Child pales in almost every respect next to the resonant A Lie of the Mind the troupes opened a week before. But the disparity seems Shepard-ish somehow, as if designed to mirror the divergent courses taken by the pairs of brothers at the two plays’ centers.

In Buried Child, the brothers are pathologically passive Tilden (Mark Rhea) and preternaturally violent Bradley (Eric Lucas), with Tilden’s long-absent son, Vince (Chris Stezin), arriving in the second act to function as a plot-advancing wild card. Also on hand is the judgmental family patriarch, Dodge (Jim Jorgensen). In A Lie of the Mind, the brothers are violent Jake (Rhea) and passive Frankie (Stezin), with Jorgensen sitting in judgment from outside the family and Lucas fulfilling the wild-card function from his director’s chair.

Both evenings hinge on the way the men in dysfunctional families react to women from outside the family group, specifically to Susan Grevengoed, who plays a pair of strong-willed heroines—a battered and nearly nonverbal one in Lie, an initially terrified chatterbox in Child—who manage to assert themselves in environments dominated by coursing testosterone. Filling out the evenings are Kevin Adams, as a pair of differently ineffectual authority figures, and Charlotte Akin, who goes from a daughter who battles a domineering mom in Lie to the domineering mom herself in Child.

Small wonder, then, that the plays seem to be covering much the same territory as they tell of recurring patterns of behavior—violence begetting violence, uncommunicativeness passed from generation to generation—in families that appear to be spinning apart. Still, seeing the evenings close together also points up the variations Shepard works on his themes.

Buried Child, first produced in the late ’70s, develops its portrait of familial creepiness in linear fashion, tracing the devolution from a diminished but still cruel patriarch through the two sons, who could be said to represent warring sides of his personality, and then showing how the grandkid who nearly gets away from the family’s monstrousness could get roped back in. The playwright’s onstage imagery is calculatedly physical—there’s a one-legged bully who gets beaten about the head with his prosthetic device, a mother so disengaged she’s actually offstage for most of her dialogue, and phallic vegetables that get shucked and peeled as a sort of counterpoint to the notions of manliness that are being verbally shredded in the script. (A Lie of the Mind, written just over half a decade later, takes a less hermetically sealed approach to an essentially similar situation, with Shepard playing out generational disputes in two families united by marriage but filled with animosity for each other.)

At the preview I attended of Buried Child, the pacing was slack and the performances scattered, so relatively little of the play’s grating humor was registering. Rhea, so visceral in Lie as a quasi-repentant wife batterer, plays the play’s most enigmatic character in a virtual monotone, while the rest of his stage family tends to bellow and shriek—which leaves the interlopers (including the grandson, who’s been away long enough to qualify) as the only vaguely human folks on the premises. The director’s staging choices, when not incomprehensible (“Mack the Knife” as interstitial music?) feel perfunctory, as if simply getting the play up and on its feet were enough.

Still, there’s that synergy thing. Keegan and Fountainhead are offering a twofer deal on the plays—buy a ticket for one and you get a ticket for the other as a bonus. My advice would be to buy for Lie, which is pretty damn splendid, and see whether you feel seduced enough by the cast and milieu to come back later. That’ll give the cast a chance to work a little more on Child. Maybe, by the time you return, they’ll have gotten it together. If not, there’ll still be those parallels to distract you. CP