Charlie and Josephine are to be married in a church on the island off the east coast where her family, the Fishes, live, the other wedding events to take place or centered on the well-off Fishes' extremely large house. Alistair and Cecil are Charlie's two groomsmen despite neither really believing in marriage, they, who do believe in love, doing whatever they can to make what they assume will be Charlie's miserable married life tolerable. Charlie, Alistair and Cecil arrive on the island the morning of the day before the ceremony, all of whom who will meet most of Josephine's very large network of family, extended family, friends and acquaintances attending the wedding for the first time, many of who border on the eccentric. As Charlie goes through the process of the pre-wedding events, including the stag party, rehearsal, rehearsal dinner, and the minister's counseling services, and beyond other problems that arise such as Baker, the Fishes' trusty servant, expressing some frustration as to his employment, Charlie begins to have doubts about marrying Josephine. As such, he tries to find a way to get out of the wedding. Barring that happening, he will try Plan B, which is to sabotage the wedding by other actions. This movie is less a "will he or won't he" make it to the church on time question, but rather a satire on the rituals associated with weddings, with excerpts from the fictional book of etiquette, "The Compleat Bridegroom", presented as title cards to those events, followed by the mess of the actual event itself.