Quatre amis américains se retrouvent à Londres pour un mariage et voient leurs vies complètement bouleversées à cause d'une révélation explosive faite devant l'autel. Ils ne se doutent alors pas un instant de l'année qui les attend, ponctuée de romances et de peines de coeur. Maya, the young communications director for a New York senatorial campaign, receives a wedding invitation from her college schoolmate now living in London. She leaves her professional and personal life behind, in favor of traveling to England and reconnecting with old friends and ends up in the midst of their personal crises. Relationships are forged and broken, political scandals exposed, London social life lampooned, love affairs ignited and doused, and of course, there are four weddings…and a funeral.