Martin gets a postcard from Clare, telling him that she's married Shane in Australia.
Everyone is preparing for Mandy's wedding. Archie has been set a series of "challenges" by his ex-marine chums, in preparation for his marriage. Matt has been persuaded to go to the wedding.
Martin goes to Mandy's hen night and meets a girl named Rachel, who's "almost exactly like Clare" (except that she isn't Irish, she isn't a nurse and her hair is the wrong colour). He arranges a date with her, during which he gives her a wig (similar to Clare's hair) and asks her if she'll speak with an Irish accent.
On the morning of the wedding, Martin gets a phone call telling him that the wedding limousine isn't available. He borrows an old Nissan and drives Mandy to the church. Matt travels in the boot. When they arrive, there's no sign of Archie. Then the best man arrives and tells Mandy that Archie has been killed in a car crash. She drives off at high speed, saying that she intends to crash the car and kill herself. Martin isn't keen on the idea, for obvious reasons, and manages to talk her out of it.
When they get back home, Martin gets a phone message from Rachel. She says that he's a "weird, twisted pervert" and she doesn't want to see him again. Apparently this reaction was caused by the nurse's uniform he'd given her as a present.
Mandy learns that Archie was killed trying to meet his final "challenge" - to get a speeding ticket on the way to his wedding.