Operation Do-Over is a time-travel book written by Gordon Korman. Mason, the main character, is best friends with a guy named Ty, they would do everything together. They could not be separated until seventh grade when a girl named Ava came into the school. They fought over Ava, and their once great friendship came crashing down faster than it started. Since then, Mason has regretted having that fight, as Ty has hated him for years now. Not only has he lost his best friend, but his parents divorced and his dog Rufus died. One day, when he was driving, he gets into a major crash and thinks he is dead, but he instead wakes up 5 years earlier in seventh grade. It takes him a while to understand, but he realizes that he gets a second chance to do everything all over again. Now, he is trying to keep his friendship with Ty, but can he do it? This was a solid book. I gave it a 4-star rating because it was a bit confusing how the time travel worked, but it kept me going until the last page of the book and the ending was great.