The Heffernans are again thinking about getting pregnant, just four months after Carrie’s miscarriage. But there’s one problem: Arthur. Now that his last friend from the senior center has moved away, Arthur naps all day. By the time Doug and Carrie get home, Arthur is full of energy and has no one but them to unleash it on. Quality time alone for the couple is impossible. That is, until Doug hires an attractive dog walker to occupy an unsuspecting Arthur: she takes him for a stroll three times a week, under the guise that she’s a student interested in learning about his World War II experiences