THE STORY SO FAR: Cleverly disguised as trees, Malcolm and the English army are steadily marching towards Macbeth's castle at Dunsinane.
Nobody really thinks you're trees, Siward and son. You're not fooling anyone.
Probably my favorite generic Shakespearean stage direction is "alarums", or possibly "alarums and excursions". Basically what it boils down to is someone blowing a trumpet offstage while lots of other someones, usually carrying spears or swords, run back and forth across the stage. This happens a lot in Shakespeare.