It’s always exciting to be introduced to a novel by a debut author that leaves us breathless when we’re done reading it. Such was the case with Garth Risk Hallberg’s City on Fire (Knopf, $30), a 900-page epic set in New York City in the mid-1970s. The story centers on an unlikely cast of characters who at first seem only tangentially connected. But as the story unfolds, their lives become curiously entangled thanks to an unsolved shooting in Central Park. Hallberg, who once taught at the Beauvoir School in the District, is too young to have first-hand experience of the era about which he writes, but he has an innate, and uncanny, ability to convey the cultural nuances of the time. His characters include teenage punk rockers, the bored heirs to a family fortune, an aspiring young writer, and a detective and journalist trying to solve the murder. Throw in the blackout in New York City in the summer of 1977 and you end up with a story that is at once edgy, entertaining, and hugely humane.