Ahern (PS, I Love You
) uses letters, notes, e-mails and instant messages to narrate her poignant second novel about thwarted love and missed opportunities. Plucky Rosie Dunne is infatuated with her best friend since childhood, Alex Stewart, but Alex has always been oblivious. After he moves from Ireland to the U.S. with his family, the two keep in touch, planning to reunite—first at Rosie's prom and, later, at college. But Rosie has the kind of bad luck you see in the movies: Alex's plane is delayed, and so Rosie attends the prom with "Brian the Whine," who promptly knocks her up. Rosie decides to have the baby, thereby missing her opportunity to study hotel management at Boston College and hang out with Harvard-bound Alex. At this point—which isn't very far in—the novel begins to suffer from an overfull mailbox. It seems that everyone in Rosie's life sends her (and each other) missives, and this flood of mail weighs the novel down as the years pass. Rosie Dunne is a worthy protagonist, complex enough to be compelling and ordinary enough to be believable. But Rosie and Alex's early, futile get-together attempts are summarized too quickly to be satisfying, and the letters between Rosie's now adolescent daughter, Katie, and her best friend, a boy named Toby, are too obviously reminiscent of Rosie's childhood correspondence with Alex. Implausibility rears its head again when characters sum up their lives in overly serious, long-winded paragraphs foreign to the chatty, impromptu format of e-mail. But the novel endears despite its flaws, thanks to Rosie and our endless appetite for stories of love finally requited. (Feb. 9)