Nico Piro, her husband, Jeremiah Cushman, and Karen Sullivan at a recent book group hosted by Arlington Public Library as part of its new Lit Up program. (Courtesy of Arlington Public Library)

On a recent unseasonably cold Thursday evening, a dozen members of Arlington Public Library’s Commuter Book Club met at Clarendon’s Le Pain Quotidien to discuss “The Cuckoo’s Calling,” the crime fiction novel by Robert Galbraith ­(a pen name for J.K. Rowling).

For the group of mostly 20- and 30-somethings, some of the discussion material was familiar, as members have been tweeting their comments via hashtag #aplrideread throughout the month.

Another group will meet to discuss the book Monday evening at Samuel Beckett’s Irish Gastro Pub in Shirlington, where the library’s Books on Tap program offers a happy-hour book club.

The somewhat unorthodox off-site book clubs, moderated by librarians, are part of the Lit Up literary program started by the county’s l ibraries in the past two years. The groups are an effort to appeal to prospective readers outside the reach of typical library programs.

Several years ago, a library-use survey found that while the library system does a good job of reaching children and older people with kids, residents in between have been underserved. That group — known as Metro renters — is made up of professionals in their 20s and 30s who tend to rent apartments near Metro stations.

“Some of us [librarians] looked around and said, ‘Hey, we’re Metro renters. What kind of programs would we like?’ ” said Nico Piro, Youth Services librarian at Arlington Central Library.

Piro is one of about 10 librarians from across the county’s library system who started Lit Up, a set of programs aimed at drawing in those young professionals.

“A lot of us on the team are children’s librarians and teen librarians, and we do all these great, fun programs for young people, so it’s nice to channel that to the older crowd,” Piro said.

The resulting programs have been a hit. In addition to the book clubs, a number of other events have been well attended. A James Bond literary-themed Ball at Artisphere drew 300 people. And Adult Recess night at the library last summer, featuring Nerf games, cardboard fort-building and oversized chess and checkers, proved so popular that another Adult Recess is planned this summer.

The Shirlington Branch Library recently held a Strategy Gaming Night, where about 20 people showed up to play Settlers of Catan and other tabletop games. The library plans to hold those events monthly. Shirlington also offers “Blind Date With a Book,” where participants can pick up a mystery read in a brown paper bag, submit an online book review, and enter a drawing to win a $25 gift card to the wine-and-cheese bar Cheesetique.

“We’ve been really excited,” Piro said of the programs. “It’s been a fun thing to be a part of.”

Are the librarians concerned that the off-site book clubs are keeping residents from visiting the libraries themselves? Not overly. Piro hopes the groups will introduce readers to the system’s e-books library and more.

“We’re hoping it’ll show them the offerings that are relevant to them,” she said.

Peter Golkin, spokesman for the library system, said he thinks the programs offer a way to loop in users to library services, even if indirectly.

“It’s a bit unconventional to have a library book club that doesn’t meet at the library, but some people may be more comfortable outside the library setting,” Golkin said.

Besides, for all they offer, libraries still prohibit alcohol.

“Having a book group meet at a local pub makes a certain amount of sense for a certain age group,” Golkin said. “It’s something they were probably thinking about doing that night anyway, and if you toss in a book discussion, you just could seal the deal. . . . I think if they come to something involving the library, eventually they’ll be stopping by one of our buildings. You’ll be getting to know at least one staff person at the event who’ll probably convince you to come by, get your card and get to see what the system has to offer.”

Lanyi is a freelance writer.