In What Patrick Does at Nighttime, Spongebob wonders what Patrick does at nighttime. Meanwhile, Patrick is looking for a cheeseburger. Patrick then goes to the BargainMart and is taken home by a police officer. Later, the same police officer and his brother tell Patrick that they think he left a book in the police car, but it turns out that it isn't Patrick's book, and it isn't SpongeBob's book, and it isn't Gary's book, and it isn't the police officer's brother's book. In the end, it turns out that it was the police officer's book, and everyone falls asleep. But then, later that night, it becomes apparent that it might not have been the police officer's book because Patrick came out of his house.