An unwelcome visitor arrives in the Lakes on the eve of Ralph and Katie's wedding in the shape of Ralph's father, whom he has not seen in more than 10 years. Louise is less than keen to have him around, as is Maurice - in part because Doug proves a far more likable person than he had imagined. Paul and Sarah's liberalism is put to the test when Mark and Joe want to strike out on their own. They decide to let the boys go for a day out on their own, but neither is able to resist checking up on them.