Graduation Day at Brown University in 1982 finds three seniors disengaged from the milestone. Madeleine skips the ceremony to visit her hospitalized manic- depressive boyfriend, Leonard, while Mitchell, the fellow she has frustrated for four years, gets stoned.Eighteen years after his widely praised debut with “The Virgin Suicides” and nine years after his Pulitzer Prize- winning “Middlesex,” novelist Jeffrey Eugenides has ended another long gestation with the “The Marriage Plot.” It’s a comic, rueful, compelling dissection of a young love triangle and the hard lessons of that “last period of total freedom,” the college years.“To start with,” he writes in the opening line, “look at all the books.” The immediate reference is to those in Madeleine’s room. Yet books are a kind of subplot and season the novel like a soundtrack.Madeleine is an English major whose senior thesis analyzes “the marriage plot” of 19th-century novels, “when success in life had depended on marriage, and marriage had depended on money.” Her shelves carry Dickens, Trollope, Austen, James.Leonard impresses her during a semiotics seminar, where the reading includes Derrida and Barthes, and a student argues that “books aren’t about ‘real life.’ Books are about other books.” The subplot thickens.The two soon embark on a relationship via three days of “having sex and eating pizza.” They banter about the adjectival forms of Joyce, Mann, Pynchon and Gaddis. They break up when Leonard mocks Madeleine with a Barthes quote. She has a fling with a semiotics fan after a party where “the bookshelves held the usual Kafka, the obligatory Borges, the point-scoring Musil.”Mitchell is the unrequited swain whom Madeleine met and unwittingly mesmerized at a toga party during freshman orientation. They come close to consummation after a train ride to her New Jersey home, during which he reads “Finnegans Wake” and she volume one of “A Dance to the Music of Time.” Even as she links up again with Leonard, Madeleine gives Mitchell reason to refuel the torch he has long carried.After graduation, she and Leonard head to Cape Cod where he has a research fellowship. But his mental state has worsened, his lithium dose has risen. When Madeleine’s mother and sister visit, the secret of Leonard’s manic depression emerges, to the consternation of parents who had raised Madeleine as “a positive, privileged, sheltered, exemplary person.”Around the same time, Mitchell and his roommate, Larry, head off to travel on the cheap in Europe and India. A religious-studies major, Mitchell packs Thomas a Kempis, Merton, Tolstoy and Pynchon. In Paris, he offends Larry’s feminist girlfriend, who is capable of sentences like: “’She’s basically a Lacanian, except she doesn’t agree that signification and language come from castration fears.’”The travelers split up when Larry discovers his inner homosexual in Greece. Mitchell spends several weeks working at a Mother Teresa Home for Dying Destitutes in Calcutta.Eugenides brings the trio together in the New York area for an ending that doesn’t quite confirm or deny a Trollope quote Madeleine used for her thesis: “’There is no happiness in love, except at the end of an English novel.’”The plot shifts smoothly among the main characters as Eugenides regularly isolates one of the lovers to fill in biographical details and tellingly change the point of view on a narrative section previously rendered. These mini-Rashomons are fun and poignant reminders that our perceptions can play as many tricks on us as memory does.There are other memories at work. Eugenides graduated from Brown in 1983 and worked in a Mother Teresa shelter in India. He roomed at Brown with novelist Rick Moody, who later wrote of his struggles with depression. Leonard also resembles the late writer David Foster Wallace, who suffered from clinical depression.Needless to say, Madeleine is the biscuit that sends Proust in search of lost time. And did I mention that Madeleine’s childhood room is wallpapered with scenes from the “Madeline” books, that Leonard is described as a Sendak creature, that architectural elements near Brown recall “a Lovecraft story”?Read “The Marriage Plot” as contemporary love fable, as elegiac nostalgia, as a writer’s celebration of writers and his own roots -- or just read it because you too still carry a torch first kindled by all those fine books you fell for in college.