The story revolves around Madeleine, Mitchell and Leonard, three college students at Brown in the early 80's and details a year in their lives. Madeleine is a romantic studying literature. Mitchell is searching for meaning by studying and immersing himself in the world religions. Leonard is a brilliant scientist with manic depressive tendencies.
Mitchell loves Madeleine but she is in love with Leonard. Leonard, meanwhile, is going somewhat quietly crazy. As they graduate from college and head off into the world, they are each seeking direction and fulfillment in their own way.
As with Eugenides' other novels, the characters are well realized and believable. He makes you care about what happens to them and where they will end up. It's a great novel and I highly recommend it.