What is the significance of malcolm's army carrying branches from birnam wood to the castle?

With crack on crack of thunder, zeus let fly a bolt against the ship, a direct hit, so that she bucked, in reeking fumes of sulphur, and all the men were flung into the sea. they came up 'round the wreck, bobbing a while like petrels on the waves. no more seafaring homeward for these, no sweet day of return; the god had turned his face from them. –the odyssey, homer read the passage. then, identify the theme that is supported by the passage. most ships cannot survive a terrible thunderstorm. the ocean is an angry beast that will tame any who try to control it. the gods have the power to control human destiny. men are willing to die to eat the delicious cattle of the gods.