By GREGORY N. HEIRES

Latchkey kids, homeless people and recovering addicts are among the thousands of diverse patrons who pass through the doors of Hamilton Fish Park Branch Library in Manhattan.

Then there was the neighborhood tough who once brazenly opened his jacket to show off a handgun tucked into his pants.

As Supervising Branch Librarian Jayne Pierce matter-of-factly described the incident, she said that the teenager brandished the weapon after she scolded him for leaping a turnstile. That evening, the New York Public Library assigned a security guard to escort her home.“It never gets boring around here,” said Ms. Pierce, who oversees operations at the library.

Many librarians enjoy a workplace with easy going patrons and a tranquil atmosphere. But Ms. Pierce thrives on the hustle-bustle of an urban branch and relishes reaching out to the downtrodden. As the head of a unifying institution in a neighborhood struggling economically and grappling with demographic change, Ms. Pierce is on a mission. She’s a social worker, community activist, teacher and surrogate parent.

“We like to reach out to the people so everyone feels a part of the same community,” she said.

The area’s 14 public schools have among the lowest math and reading scores in the country. Hamilton Fish has its writers, professors and professionals. But most of its patrons are from poor and working-class families, including adults who can’t read, children from unstable homes and senior citizens with only Social Security to live on.

Ms. Pierce, who has worked at Hamilton Fish since 1990, reaches out tirelessly to the schools. Virtually no visiting elementary pupil can escape without signing up for a library card.

The different languages in the adult and children’s book collections show that the branch?is working hard to meet the needs of the neighborhood’s immigrants, who are predominantly Puerto Rican and Dominican with growing numbers from El Salvador, Bangladesh and China.

Ms. Pierce’s work has made the library an anchor of the community. Last year, she collaborated with the Parks and Recreation Dept. and the American Museum of Natural History to set up an astronomy program for children. With The Streetwork Project, she encourages homeless teens to visit. And Ms. Pierce runs a monthly poetry reading and writing workshop with women in recovery at the nearby Lower East Side Harm Reduction Center.

Ms. Pierce connects with the pulse of the neighborhood. She is outgoing and resides in the area. People stop her in the street to ask about library services. She shops in the local bodegas, where she occasionally treats library kids to lunch.

HER PRESENCE is striking as she wears 1950s-style “cat eyes” glasses and often sports an Indian bindi on her forehead, numerous bracelets and necklaces, and colorful outfits.

Residents remember when Ms. Pierce married her husband, Michael Lee, and when she was expecting. Her 5-year-old daughter, Ena Pierce Lee, is a regular patron herself. Ms. Pierce used to serve on the youth board of Community Board 3 and now heads the Parents’ Association at Ena’s school.

Apart from her community outreach, Ms. Pierce keeps busy with her branch librarian responsibilities of overseeing the staff, fighting for a good budget, building local political support for library services, ordering books and scheduling events. She has also held onto her work as a children’s librarian. For her, building a child’s self-esteem is as important as helping develop a love for reading and learning.

“I love working with kids,” said Ms. Pierce, who studied to be a children’s librarian at Queens College. “Kids are the most attentive, grateful and needy of our society.They need an advocate because they don’t have rights in an adult world.”

She is active in the union’s campaign to boost librarian salaries in the New York Public Library system, which periodically shuts branches because it cannot keep or hire staff at current pay levels.

“I have been tempted to leave to make more money, but the rewards are greater here,” said Ms. Pierce. “You are here for the community.”