Here's the breakdown:
* The Ghost's Account: Old Hamlet's ghost tells Hamlet that he was murdered while sleeping in his orchard. Claudius, Hamlet's uncle, poured poison into his ear, leading to his death.
* The Poison: The poison was not specified, but it was likely a quick-acting substance meant to be absorbed easily.
* The Motive: Claudius, motivated by greed and lust for the throne and Hamlet's queen, Gertrude, killed his brother and took the throne.
This is a key plot point in the play as Hamlet's quest for revenge against Claudius is fueled by the ghost's accusation.