 From references in other contemporary works, Kyd is also assumed to have been the writer of an early, lost version of "Hamlet" (the so-called "Ur-Hamlet"), with a play-within-a-play interlude.William Shakespeare's "Hamlet" retains this device by having Hamlet ask some strolling players to perform the "Murder of Gonzago".The action and characters in "The Murder" mirror the murder of Hamlet's father in the main action, and Prince Hamlet writes additional material to emphasize this.