A prayer to god to be merciful whilst destroying enemies, specifically Lebanon, Sharon, Carmel and Bashan. Isaiah has so many enemies he's not even giving them their own chapters anymore, he's quadrupling up!
Their punishments: their schemes will go awry, bad breath, people consumed by fire. The last of course will terrify the people of Zion into submission. You know what really terrifies people into submission? Seeing this kind of punishment meted out to their own kind, not to the Assyrians.
Rewards for good people: going to heaven, free bread, a chance to look at the king every day. At first he'll miss his old life, but eventually he'll get used to the parties, peace and free love of Jerusalem, where people never get sick.
More threats! This time it's against pretty much everybody. The slaughter will be so bad the blood will run down from the mountains. At first god is just pissed in general, but eventually he settles on Edom as the target of his wrath.
To massacre the Edomites, he's going to use his sword, yes, but also unicorns, because god is a particularly vicious 12 year old girl. Then he's going to burn everything forever and ever. Global warming is not man-made, ya'll! It will be so bad that only owls and dragons and satyrs will live there.