For the Baby's Name, We're Debating Between "Kyle" and "Maher-shalal-hash-baz"
God tells Isaiah to go write "Maher-shalal-hash-baz"—which means "quick to the spoils, quick to the prey"—on a tablet, and have two particularly trustworthy priests attest to it.
So, Isaiah goes and impregnates his wife, the prophetess, and she gives birth to a son.
God instructs Isaiah to name the son, again, "Maher-shalal-hash-baz." (That's not exactly like naming your kid "Apple" or "North West"—or, wait… yeah, it's exactly like that.)
This is because, before the son even knows how to say "Mother" and "Father," Damascus and Samaria will get crushed by the King of Assyria—his name describes what Assyria is going to do to those places.
Because the people have "refused the waters of Shiloah that flow gently" and acted cowardly before the King of Israel's threat of invasion, God says he's going to let the King of Assyria launch a full-blown assault on everyone—Israel, Judah, and Aram—which will fill up and overtake the land.
A short hymn follows, warning people that if they band together (against this threat) they will end up being dismayed; whatever they do to prepare, they'll just be dismayed and overwhelmed (bummer). Their plans and schemes won't stand—only God will.
Ignore the 'Truthers'
God tells Isaiah not to listen to the people and the things that they claim are conspiracies against them. God is the only one Isaiah should fear and revere.
God will be like a rock that both royal houses of Israel will stumble over. And many people are going to stumble over that rock.
Isaiah says that all this testimony should be bound up and sealed with his disciples. He will remain waiting for the Lord, who is now hiding his face from the House of Jacob, and Isaiah will continue to put his hope in God.
He says that he and his children are signs that God has sent to Israel, to warn them.
Isaiah ends the chapter by warning people against consulting the ghosts or foreign gods to try to receive aid and destruction. It won't work. They'll end up cursing their leaders and the gods they were worshipping, and will be destroyed in the end—only darkness and distress can awaken them.