Molly was freaked out by Laurena's devotion to her religion.

Laurena was turned off when Molly described herself as stubborn.

Under normal circumstances, their many differences would have kept them apart. Instead, their differences brought them together.

Last summer, Laurena, who is black and lives off City Line Avenue; Molly, who is white and lives in Mt. Airy; and 14 other high school juniors from all over the city were chosen to study the roots of anti-Semitism and slavery during a monthlong trek through 10 states.

AM I MAKING MYSELF CLEAR? Operation Understanding participants Melissa and Jamal at 17th and JFK where the group was departing for a retreat. : Michael T. Regan

"We don't want them to break down walls," says group leader Janet Luterman. "We want them to open doors."

Local African-American and Jewish leaders founded Operation Understanding in 1985 in response to increasing tension and waning communication between the two communities.

Beyond promoting dialogue, the program aims to develop leaders. OU inspired similar programs in Washington, D.C., San Diego and St. Louis.

The Philly organization originally ran two free programs each summer. One, like Laurena and Molly's trip, featured domestic travel.

The other sent students to the West African nation of Senegal as well as the Jewish state of Israel. After the summer 2000 trip, the international program was temporarily put on hold when the second intifada, a wave of Arab-Israeli violence and the Sept. 11 attacks made the Middle East too volatile to visit.

This year, however, the OU board decided to reinstate the international trip. The board has not yet decided whether OU, which is funded through donations, will bring back both trips next year.

But on a warm Sunday afternoon a few weeks ago, no one was too concerned about the distant future.

Thirty-some students—last summer's alumni and the '06 crew—formed a circle in the lush East Mt. Airy back yard of one of the students and shouted out things they might have in common. "Phillies fan!" "Water ice!"

When a brawl between a neighbor's mutt and a Jack Russell terrier put an end to the icebreaker, they tried another. This time, alumni gave advice to the newbies.

"Pack light," says Laurena, who passed around prom pictures and admitted she got caught with a cell phone against trip rules. "I brought way too much."

"And don't let anyone else do your laundry," a boy says, locking eyes with Molly.

"I'm just not good at domestic things!" she replies in defense.

Despite their differences, Molly grew to understand Laurena's spiritual devotion also meant she was a loyal friend with maternal instincts. She traveled with an iron and made sure everyone was awake on time.

"Things we didn't like about each other transformed into things we did," says Molly, who wore a Live 8 T-shirt and a "Darfur: Not on our watch" bracelet.

She was voted "Most Liberal" in her class at Central High School, but Molly worried she might have been closing herself off from certain perspectives. After the trip, she realized, "Becoming friends with people who are so unlike me made me feel like I was as open-minded as I hope to be."

To complete their mission, they had to let go of stereotypes and see the humanity in each other's lives.

Laurena overcame some personal hurdles of her own at an OU wilderness retreat before leaving for the South. Standing on a platform 5 feet off the ground peering down at two fellow students, she thought, "I do not trust them."

But she relied on faith, yelled, "Ready to fall! Falling!" and let go. Her friends stretched out their arms and yelled back, "Ready to catch! Catching!" The experience inspired her to be first to tackle the next obstacle, scaling an 8-foot-tall wall.

Although Laurena may not realize how much the trust-building exercise had to do with cultural understanding, she learned one thing. "I can do anything with my team," she says. "We can change the world together."

Still, students like Leah Smith, who attends the High School for the Creative and Performing Arts with Laurena, aren't quite sure what to expect when they board the plane today.

"I'm scared about some of the things I will learn," she says. "But I don't want to be ignorant."

It's true, says '89 alum and board member Elliot Weinbaum, that besides forming close personal friendships, the international travel component is integral to the "consciousness-raising" experience.

For example, his group brought toys to Senegalese children in the village of Saam Njaay who had few material goods. They were greeted with singing, dancing and hugs. The cultural exchange was more meaningful to him than any meeting in the homogenized U.S., "where we're all wearing clothes from the Gap and we all shop at Wal-Mart."

In OU lingo, the students are "cultural anthropologists," not tourists.

In addition to orientation sessions prior to the trip, students visit community groups after they return.

Weinbaum remembered going to a predominantly black elementary school where the students had never met a Jewish person. He later talked to senior citizens who told him years ago the city's blacks and Jews lived in the same neighborhoods, and shared what's now called a "socioeconomic class."

"This opportunity six thousand miles away," he says, "it served as a conduit to learn more about people six miles away."