When playwright Michael Whistler arrived for a session with Wyndmoor family therapist Abby Ruder earlier this year, it was hardly your typical hour - more like four. And Whistler didn't even have personal issues that needed a going-over.

What he had was the script for Little Lamb, now in previews and opening Wednesday in its InterAct Theatre Company world premiere. It tackles, in a blend of issues of the sort that has become an InterAct hallmark, multiple themes: adoption, in this case gay adoption; building transracial families; and bigotry based on stereotypes in Latino, African American, gay, and religious communities.

These are among the root issues that define the professional life of Ruder, a noted specialist who for a quarter-century has guided clients in the ways of adoption, advanced reproductive technology, and parenting. Her key interests involve open and transracial adoptions for both traditional and alternative families. Little Lamb is about just that - a mixed-race gay couple set on adopting an African American baby. Religious beliefs - the couple's, a social worker's, the birth mother's - figure large in the scenario.

Ruder "told me about the history of transracial adoptions, about forming a transracial family, and taught me how to use the language [about adoption] properly," says Whistler. "She helped me understand what the laws were, and through her, I met adoptive families."

Little Lamb, which stars the dynamic actor Frank X among a cast of five, has changed in subtle and basic ways since Whistler's first talk with Ruder.

When current laws raised questions about the original plot, in which the birth mother came from another state, Whistler moved her to the same city as the two men looking to adopt. The role of the play's social worker has been fleshed out, and Ruder has met with Kaci M. Fannin, who plays the part and was herself a social worker in Austin, Texas, in the '90s before turning full time to acting.

Ruder gave Whistler a grounding not just in the laws, but in the emotional dynamics at play - just as she does for her clients. Whistler, in turn, presented Ruder with a play that struck her personally; it was a new experience for her, she says, to encounter a piece that was "putting a lot of my life's work into an art form."

As audiences, we can't directly see or even sense that meaty new plays are much more than matters of plot-creation and character-building. Playwrights, at some point, often take on the same sort of research as lawyers building cases, physicians considering health histories, social service workers dealing with clients, and journalists doing basic reporting: They go fact-finding.

This research is more obvious in historical drama, or plays built with real people in mind - Bruce Graham's new play Something Intangible, now at the Arden, for example: It's about two brothers who are not Hollywood's Disneys, but are based on them.

Little Lamb is entirely a fiction - it has no Disneys to build on, only Whistler's created-from-whole-cloth characters. Whistler, 46, who has been writing plays for 10 years and heads the theater-arts program at Montgomery County Community College, began talking with adoptive couples as his script came together. Several people pointed him to Ruder.

InterAct sent her a copy of his just-finished first draft, already informed by discussions Whistler had had with the adoptive parents. "He did a fabulous job at the research," Ruder says, "and it was a real kick for me to be asked to fill in holes of all the things he wasn't able to know about."

Whistler is a gay man - his partner, James Haskins, is managing director of the Wilma Theatre - who was deeply affected by the role the Christian right played in reelecting President Bush in 2004, which led to his decision to write Little Lamb.

He was raised "in a very open, loving, and Christian household," in Syracuse, N.Y., and his father was dedicated to social justice. "I was stunned at the power of a fundamentalist base" that focused on the issue of gay marriage to campaign for Bush. "It intrigued me and hurt me, to be honest with you. I felt so betrayed."

So he put his reaction into artistic action: "I wanted to look at something that has to do with the body politic, and the relationship between gay men, African Americans, and conservative Christians."

Whistler is not an adoptive parent, so he has never faced the challenges that any adoptive parent faces. At first, he talked with a traditional adoptive family, then he met alternative families.

He also watched a lot of TBN, the Trinity Broadcasting Network, "and it was fascinating to see how Bible stories I knew were being used in very different ways than the stories I grew up with. It was very clear to me how political a lot of these groups have become."

From this, he says, "I wanted to create five characters working very hard to do good in this world. The ways they see to do good don't really exist in the same world."

Whistler, who has worked in sessions with other playwrights at InterAct, was encouraged by a $2,500 development grant the theater company awarded him as part of its 20/20 New Play commission program, now two years old. Little Lamb is the first work to be produced from that program.

Since it was launched in 1988, InterAct has always pursued new works, and its producing artistic director Seth Rozin, who is staging Little Lamb - its 25th world premiere - says the commissioning program is a response to a pool of fewer new works and the jousts over producing rights that make them harder to acquire. The project gives InterAct "a stream of plays we have a direct interest in and some form of control over," so the company can schedule and produce them.

In fact, it was Rebecca Wright, InterAct's literary manager, who made initial contact with Ruder to assist the playwright. "Adoption is complicated," Ruder says. "For people who don't have that kind of exposure and experience, it was real foundation work for them. It's Michael's creation, but in order to make it work even better, he needed a solid foundation, and it was wonderful for me to be able to supply some of that."

For Whistler, the research is a solid base for Little Lamb's larger meaning. "This play," he says, "is about retrieving the Christ my father gave me, who really did see and believe in man being a steward on this Earth through his mission."

at 215-854-5727 or hshapiro@phillynews.com. Theater

Little Lamb

InterAct Theatre Company through June 28 at the Adrienne, 2030 Sansom St.

Tickets: $15-$28. 215-568-8079 or www.interacttheatre.org.