It's now night, and Don, apparently having passed out for a time, comes to in his front seat. He lights a cigarette, and in front of him, a train passes, which we see reflected in his windshield. Yup, the machine of suburbia keeps chugging along even when you take a nap, Don.
Betty, rubber gloves on, is doing dishes and smoking as a Cheerios commercial plays on the radio. She hears a car pull in, and tries to take her gloves off, but her hands are shaking again, so she abandons the effort. Sally happily greets Don, and I was joking about the slow thing before, but...she didn't notice that her dad semi-ruined her party? Betty hears barking, and comes into the living room to see Don sitting with the kids and a golden retriever he apparently picked up from the all-night pound over in Chappaqua. Betty somberly admits she doesn't even know what to say, and Sally names the dog "Polly." Given her attitude, she just needs another one to call "Anna." Betty walks out in disgust as Don drunkenly wishes Sally a happy birthday, and then he rests his head on the couch as Bobby Vinton's "PS I Love You" plays into the closing credits.