In 3 sentences:
Scene 5 - Macbeth learns that his wife has died and receives a prophecy that seems to protect him from harm. However, news arrives that the trees of Birnam Wood are advancing on his castle at Dunsinane. Macbeth prepares his forces to leave the castle and fight.
Scene 6 - Malcolm's army nears Dunsinane castle and they discard their branches, fulfilling the prophecy. The battle is sounded.
Scenes 7-9 - Macbeth fights Young Siward and Macduff, believing the prophecies protect him, but learns from Macduff he was not "born of woman," defeating Macbeth. Macduff presents Macb