After Michael(Dermot Mulroney) tells his best friend, Julianne(Julia Roberts) that he is getting married in four days, she goes straight to Chicago to help him get through. But she has every intention to stop the wedding and steal the groom from Kimberly(Cameron Diaz). Over the next three days, she tries everything to split them up. Finally, on the day of the wedding, Jules tells Mike she loves him and kisses him, but to her disadvantage, Kimmy is watching them. Now Michael has to decide whom he loves most.