The Adventures of Huckleberry Finn is an 1884 novel by Mark Twain, detailing the travels of the titular character as he flees civilization with an escaped black slave, Jim.
The story is told as if narrated directly by Huck Finn, who skips around and forgets important details. As a vernacular, dictated novel, the story is told in straight order, without long flashbacks or foreknowledge of coming events (see Huck's astonishment at the actual status of Jim, for example). In this sense, it doesn't follow any specific narrative path, instead being a casual, meandering portion of Huck's life. Although there is danger, tension, and resolution, much of it (such as Huck's brief masquerade as a girl) seems random, having little long-term effect on the plot.
Broadly speaking, it falls under the generic three-act structure: Huck takes on a quest (help Jim escape to the North), undergoes trials (his abusive father, moral conflict over Jim, a violent family feud, the Duke and King), and finally wins victory (Jim is freed).