When Hamlet returns he finds 2 gravediggers, clearing out a grave, and when he finds out who's grave is being dug he is hurt.
The Fencing Match
Hamlet is telling horatio about how he found the letter that the King sent with R and G with Hamlet to England, and he found out the letter was telling the king of England to kill Hamlet, but Hamlet takes the letter and writes a new one telling the King to kill r and g.
Osric comes in and tells Hamlet that the King has made a bet with Laertes that Hamlet will beat him in a fencing match and to come down and fight him, and Hamlet doesn't know that the King and Laertes are planning to kill him during the fencing match
Laertes and Hamlet are fighting, and the Queen drinks the wine that was poisoned and laetus scratches Hamlet with the laced sword, and then Hamlet scraches Laertes with the laced sword, and he kills Claudius
After Hamlet has gotten his revenge Hamlet falls to the floor and is dying, and before he dies he says that Fortinbras will be king and that he has his vote
Once Hamlet died Fortinbras and his army charge in planning to overtake the throne but, walk into everyone dead and Horatio ask him to let him tell everyone what happened here, and Fortinbras makes himself the King and gives Hamlet a soldiers funeral.