In "The Innocents Abroad" Mark Twain assumes two alternate roles: at times the no-nonsense American who refuses to automatically venerate the famous sights of the odd world, or at times the put upon simpleton, a gullible victim of flatterers and frauds and an awe struck admirer of Russian royalty.
In "Roughing It" Marks actual and imagined adventures when he escaped the Civil War and joined his brother, the recently appointed secretary of the Nevada Territory.
In "The Adventures of Tom Sawyer" it is set in St. Petersburg, Missouri. Tom and his friend Huck Finn witness a murder and they never tell anyone. The wrong man is accused of the murder. One day while Tom and his girl crush are walking in a cave on a school field trip, they run into the original killer. They trap him in the cave and leave him there to starve to death.
In "The Prince and the Pauper" it is set in 1547 and it tells the story of two boys who are identical in appearance. Which the boys actually replace each other throughout the book.
Throughout "Life on the Mississippi" Mark explains details about his life living on the Mississippi River. He gives many details about different steamboats blowing up and killing many people.
In "The Adventures of Huckleberry Finn" Huck and his slave run away going down the Mississippi River on a raft. Jim is constantly being contracted with the effects of a corrupt society because he is colored. This books traces the adventures of Huck and his slave Jim.