Leave it to Thomas Pynchon to capture what is exhilarating as well as truly frightening about the Internet. His Bleeding Edge (Penguin Press, $28.95) is set in New York City in 2001, where Maxine Tarnow is a gun-toting fraud-investigator and the mother of two young boys. She’s not sure of the status of her relationship with her ex-husband, Horst (Facebook has yet to define it for her), but her world begins to unravel when she investigates a suspicious computer-security firm and its brilliant but troubling CEO. Guided by her own code and a lot of quick thinking, Maxine makes her way through one of the most entertaining portraits of Gotham to hit a novel in decades. With Bleeding Edge, Pynchon makes a welcome return to the realm of mystery and the ridiculous, delving into the far reaches of the Web and the subway system with equal abandon.