Heyyy : )

O. Henry Ending: Also called a trick ending or a surprise ending, this term refers to a totally unexpected and unprepared-for turn of events, one which alters the action in a narrative. O. Henry endings usually do not work well with foreshadowing, but particularly clever artists may craft their narratives so that the foreshadowing exists in retrospect.The term comes from the short stories of O. Henry (a pen name for William Sidney Porter), which typically involve such a conclusion. Note that an O. Henry ending is usually a positive term of praise for the author's cleverness. This is the opposite sentiment from a deus ex machina ending, in which the unexpected or unprepared-for ending strikes the audience as artificial, arbitrary, or unartful. A plot twist is a change in the expected direction or outcome of the plot of a novel, film, television series, comic, video game, or other work of narrative. It is a common practice in narration used to keep the interest of an audience, usually surprising them with a revelation. Some "twists" are foreshadowed and can thus be predicted by many viewers/readers, whereas others are a complete shock.
When a plot twist happens near the end of a story, especially if it changes one's view of the preceding events, it is known as a surprise ending.
A surprise ending is a plot twist occurring near or at the conclusion of a story, an unexpected conclusion to a work of fiction that causes the audience to reevaluate the narrative or characters. 1. A plot twist is to make a reader assume that an event happened due to a particular character’s actions and when they couldn’t be more sure of the false trail you have put down you give them that last little detail that reveals everything and turns the entire situation upside-down.
Twist endings surprise and delight readers, so that they seek out more books by you and tell all their friends that they have to read your books.