The plot in HAMLET develops as following:
Rising Action: Hamlet seeks to determine his uncle's guilt
The rising action in a plot is the series of events that build towards the point of greatest interest. In this particular play, Hamlet has suspicions about Claudio's involvement in his father's death.
Inciting Incident: A ghost tells Hamlet that Claudius murdered his father
In a plot, this event catches the reader's attention into the story. In the play, Hamlet's father's ghost tells him his brother murdered him which incites the reader to continue reading to find out what happens next.
Climax: Hamlet murders Polonius
This is the most intense, exciting part of the plot. In the play, the climax is when Hamlet murders Polonius unintentionally mistaking him for Claudius
Falling action: Fortinbras invades Denmark
This action follows up the climax and its when the main problem gets resolved, in this case Fortinbras claims his late father's territory in Denmark
Hope this helps