Photo by Anahuac Valdez; Totem Roles-Alma Martinez and Lakin Valdez deliver powerful performances as Mama Chu and Cajeme in El Teatro Campesino''s Mummified Deer.

To make peace with one''s family before dying is a common desire, but in the case of Mama Chu, there are, as they say, complications. Mama Chu is the 84-year-old woman at the heart of Mummified Deer, the first new play in 16 years by Luis Valdez, founder of El Teatro Campesino. Valdez premiered the play in 2000 at the San Diego Repertory Theatre, where he was then in residency; it is now receiving its Northern California premiere at the company''s home in San Juan Bautista.

The complications in this multi-generational saga arise from a troubled family tree and an uncertain sense of ethnic identity. Drawing from Indian and Catholic mythology, Mexican politics, internalized racism and old family lies, Mummified Deer abounds in secrets and revealed truths, and this review will not give away any of them. What can be said is that at its heart the play is an investigation into the Sonoran Yaqui roots of an important, if neglected, chapter in American history.

The story begins with Armida, granddaughter of Mama Chu, who has returned to San Diego from Berkeley upon hearing that her grandmother is ill and in the hospital. The play takes place in 1969, and Armida has thrown herself into the radical politics of the time. In doing so, she has become a stranger to her family. That family includes her aunt Oralia, her uncle Profe, and her young cousin Tilly. Armida was raised by Mama Chu after the death of Agustina, Armida''s mother. The whole family harbors a collection of unacknowledged emotional scars that continue to cause conflict.

Art that speaks urgently from and to the heart has always been one of El Teatro Campesino''s strengths, and this play continues that tradition. For this production, the stage itself has been fashioned into a womb-like space. What lies inside Mama Chu''s uterus is one of the play''s mysteries, and the striking set design takes viewers inside, into a mysteriously fluid world of dreams, myths, and memories. The outstanding use of sound and lighting transforms old Yaqui truths into the living blood and the beating heart of Mama Chu.

The play''s atmospheric strengths are especially important in the first act, which otherwise suffers from too much information that is presented too quickly and without dramatic weight. One has the sense early on of cramming names and dates for a history quiz.

The second act is considerably more successful. Here, Valdez uses the engaging device of having stories enacted for the audience as they are narrated to Armida by various characters. The value and power of history and memory are shown rather than explained, which allows the audience to participate in Armida''s, and Mama Chu''s, journey to the truth.

The pace also picks up in the second act, creating a theatrical, occasionally dizzying swirl that fortunately is anchored by several excellent performances. As Mama Chu, Alma Martinez inhabits the stage with fearless commitment. Even when she is nearly immobile on her hospital bed, Martinez radiates great depth of feeling. Estrella Esparza, as Armida, seems overly tentative in the first act. Her character, too, has its own demons to deal with, and one would like to sense more of that tension. But Esparza''s performance comes alive in the second act, as does the play itself, when masks begin to fall and what is at stake becomes more clear.

Other strong performances include Lakin Valdez, athletic yet vulnerable as the Deer Dancer, and Kinan Valdez, demonic in clown makeup, as a pivotal character in the thicket of Mama Chu''s past. Both men invest their roles with intelligence and grace. Rosa Escalante chews the scenery as Armida''s uptight aunt who, like everyone, has her own painful story. Anita Reyes'' rendering of Agustina mirrors the play''s own development from caricature into a tender awareness of hard choices. Her marvelous performance can be seen as a microcosm of the play itself, in which an excess of humor and physical comedy (a long, rowdy caveman skit should be axed) finally reveals what in essence is a ghost story. Similar in theme to Beloved, the haunting novel by Toni Morrison about slavery, love and sacrifice, Mummifed Deer movingly illustrates how the past is forever generating fresh meaning, often posing more questions than it can answer. "What do any of you know about me?" Mama Chu cries out during one of the play''s many powerful scenes. It''s a question everyone should ask themselves, for its answers may contain the seeds of freedom.

Mummified Deer plays at Mission San Juan Bautista, 705 4th St, San Juan Bautista, through May 26. Performances are at 8pm Thursday-Saturday and 5pm on Sundays. Thursday tickets are $7; all others are $14. 623-2444.