When I was in high school, we were reading Macbeth and got to the bit with the witches and the three spirits... one of which is described as "an armed head", and the teacher was going on about how nobody knew exactly what that description meant, was it a head wearing a helmet? What was Shakespeare getting at?
So I raised my hand... "I hope I'm not giving away the ending or anything, but Macbeth is beheaded at the end... it's an arm holding a severed head."
Armed head: "Macbeth! Macbeth! Macbeth! Beware Macduff! Beware the Thane of Fife! Dismiss me. Enough."
(Macduff beheads Macbeth)
Bloody child: "Be bloody, bold, and resolute. Laugh to scorn The power of man, for none of woman born Shall harm Macbeth."
(Macduff was not born of woman, they tried to abort him and he was born bloody.)
Child crowned, carrying a tree: "Be lion-mettled, proud, and take no care Who chafes, who frets, or where conspirers are. Macbeth shall never vanquished be until Great Birnam Wood to high Dunsinane Hill Shall come against him.He descends."
(Macduffs forces disguise themselves with tree branches to march on Macbeth).
Each spirit directly states through their description and dialog how this is all going to end, but you only see it on a 2nd read.