Donna won't listen ("One of Us"). She hates Sam; at the end of their affair, she said she never wanted to see him again. But it seems that Sam was the man Donna cared about the most, and both of them wish they could go back to the start ("SOS"). At the beach, Harry asks Tanya what the father of the bride ought to be doing for Sophie's wedding. Tanya explains that for her part, her father gave her his advice and then paid. Pepper, one of the guys who works at Donna's taverna, makes advances to Tanya, but she rebuffs him ("Does Your Mother Know"). Sky finds out what Sophie has done in inviting Sam, Harry and Bill to the wedding. He accuses her of wanting a big white wedding only so that she can find out who her father is. He's very hurt that she kept this plan a secret from him. He storms off just as Sam walks in. Sam tries to give Sophie some fatherly advice by describing his failed marriage ("Knowing Me, Knowing You"), but Sophie isn't consoled. Harry offers to Donna to pay for the wedding, and they reminisce about their fling ("Our Last Summer"). Sophie arrives and Donna helps her get dressed. She can't believe her daughter is going to be a bride ("Slipping Through My Fingers"). Donna admits that her own mother disowned her when she learned that she was pregnant. They reconcile and Sophie asks her mother if she will walk her down the aisle. Sam arrives and tries to speak to Donna again, but she doesn't want to see him, and asks him to leave. He refuses, and a bitter confrontation ensues. Donna tells Sam that he broke her heart, presumably when she found out he was engaged ("The Winner Takes It All"). It emerges that the two still love each other dearly, albeit against Donna's better judgment. Rosie is making final preparations in the taverna when Bill arrives. He's upset because he has received a note that Donna will be walking Sophie down the aisle. Bill reaffirms his commitment to the single life, but Rosie has become attracted to him, and urges him to reconsider ("Take a Chance on Me"). They are about to have sex in the taverna, but the guests arrive, leaving Rosie quite stunned. The wedding begins, with Donna walking Sophie down the aisle. Before the