Granma Mainland arrives just in time for the wedding and, to Katie Morag's delight, Grandad Island arrives with her, though no-one can explain to Katie Morag why this doesn't seem to make Grannie Island happy. But during the wedding party, with her customary ingenuity, Katie Morag succeeds in making Grannie Island enjoy the wedding just as much as everyone else. 

Neilly Beag asks Granma Mainland to marry him and she says yes. Everyone is excited except Grannie Island, who is not impressed. Katie Morag thinks that all the wedding planning must be making her miss Grandad Island. And that's when she has one of her big ideas!