The best plays, it seems, are the hardest to describe. Often, the minute someone senses that a play I am describing contains material that is complex, unhappy or uncomfortable--plays commonly thought of as "difficult"--their eyes glaze over and they ask if I've seen any good comedies lately. Last weekend I saw two "difficult" shows: Suzan-Lori Parks' Topdog/Underdog and Robert Ernst's Catherine's Care. The first is good. The other is very good, but already I am struggling with how to best describe them so you might actually envision yourself going out and seeing them. Because you should.

With Topdog/Underdog, which won the Pulitzer Prize for Drama in 2002 and was nominated for two Tony awards that same year, Actors Theatre makes its biggest, boldest move in a season it has otherwise loaded with safe, mainstream, decidedly non-"difficult" plays. Parks--whose experimental works are a blend of history, mythology and dreamscape drama--uses the tight two-person structure of Topdog to dabble in ideas about the characteristics, beliefs and wounds we inherit, from our parents, our society and the collective culture of our race and ancestry. Specifically, Parks looks at the condition of African Americans, though the wider issues are as humanly all-encompassing and identifiable as the story of Cain and Abel.

Lincoln (Michael Asberry) and Booth (David E. Moore) are brothers, their adversarial names a cruel joke from a father whose sense of humor was better developed than his sense of loyalty to his family. Living on their own since Dad walked out while they were still boys (Mom had already split years before that), Lincoln and Booth, now in adulthood, are devoted to one other, as protective and generous as they have the means to be. They are also rivals, trigger-cocked in a state of constant competition and one-upmanship.

Lincoln appears to be the better adjusted of the two. Played with reserved intensity by Asberry, he was once the king of street hustlers, master of the Three-card Monte con game. When tragedy struck, he quit and is now working in a shabby seaside arcade, dressing up (in whiteface) as Abraham Lincoln, waiting for paying customers to shoot him in the head with a cap gun.

Lincoln brings his pay home to the one-room apartment he shares with Booth, who is an agile shoplifter (as demonstrated hilariously in one well-done second act scene where he produces piles of boosted goods from under his clothes). Booth aspires to learn the lucrative three-card con, if only Lincoln would teach him the secrets of the hustle. "You know I don't touch the cards," Lincoln calmly reiterates, as Booth, lamely emulating his brother's moves, practices the game and the patter in front of a mirror.

Booth, as written, is an electrifying bundle of angry, self-deluded energy and oversized, unattainable dreams, and Moore captures his manic instability without crushing the desperate craving for respect or the fragile affection he obviously feels, a bit resentfully, toward his older brother. As the title suggests, Topdog/Underdog is a play in which the characters take turns turning the tables on each other, always strategizing how he might gain the upper hand. The quality of the acting is unquestionably high-caliber, arguably the finest two performances given in an Actors Theatre production since the company moved to its new Sixth Street Playhouse digs two years ago. Each actor has the ability to communicate volumes while speaking only a few words, as when Lincoln warns Booth with a calm but terrifying threat, "Don't push me."

The writing, though gorgeously powered by the urban street talk and rapid-fire vernacular of African-American culture, sometimes suffers from the plotting structure and leap-frogging character turns of the grand Greek myths and Biblical fables that inspired Parks. Lincoln is said to be a master of the con game, but when we finally see him work the cards, it proves to be less than dazzling, and some of the character's more extreme revelations might have been better hinted at in the performance that leads up to them.

The direction by David Lear is tight and intimate--made more so by Lear's decision to place some of the audience on stage observing the action close-up--and the show-stopping contest between the brothers is paced so well, so infused with heartbreak and danger, the mounting tension is nearly unbearable.

There is tension, too, in San Rafael's ALTERTheater's "experimental musical" Catherine's Care, but it is gentler and somehow sweeter, the tension of someone waiting for the last and final shoe to drop. Impeccably and daringly performed by a cast of four--Tamar Cohn, Craig Jessup, Jenna Johnson and Carla Spindt--and inventively directed by Jon Tracy, Catherine's Care was written by Robert Ernst, a celebrated experimentalist and the co-founder of the legendary Berkeley theater troupe, the Blake Street Hawkeyes.

Ernst crafted the script through a series of actor-writer-musician workshops, and tells the story--or the last chapter, anyway--of Catherine (played with tremendous force and focus by Johnson), an independent, defiant woman whose life and belongings have been reduced to one room in a care facility for the aged. As she slips in and out of sedated sleep, she encounters people from her past, including her husband (who died young and now seems to have become a crow) and a younger version of herself, whom she doesn't much like.

This is an unconditionally odd play, as strange and illogical as a hallucination. Characters frequently burst into song, backed up by a live band that includes playwright Ernst on drums and harmonica. Catherine, in pain and barely able to move, is set free only in her dreams, which include disturbing, unexplained images of violence and that crow-husband guy, who shows up to snuggle comfortingly when Catherine is at her lowest.

Performed with minimal props on a stretch of carpet in a former thrift store, the show is as spare and stripped down as Catherine's existence, but like Catherine, is so much more than the reduced sum of its parts. This is bravura theater work, bold, brave and different. By the time it reaches its inevitable conclusion--joyous and sad and heartbreaking all at once--Catherine's Care has become that most difficult to describe of all plays: an overwhelmingly emotional drama that works magic on the heart by first baffling the brain.

'Topdog/Underdog' runs Thursday-Sunday through Feb. 24. Thursday-Saturday at 8pm; matinees, Saturday-Sunday at 2pm. Sixth Street Playhouse, 52 West Sixth St., Santa Rosa. $17-$25. 707.523.4185. 'Catherine's Care' runs Thursday-Sunday through Feb. 18. Thursday at 7:30pm; Friday-Saturday at 8pm; Sunday at 5pm. Post-show discussions Feb. 11 and 16. 1557 Fourth St., San Rafael. $20. 415.454.2787.

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