Jeremiah goes to the king and tells him he's going to die in peace. Then he tells him to set the Jewish slaves free. So they do, for a bit, but then they enslave them again. Which pisses god off, because the subtitle to this book might as well be '1001 ways to piss off god.' And so he threatens them with the usual: plague, famine, war and enslavement.
Jeremiah invites the Rechabites over to the temple for a drink. It's the cheapest date ever, since the Rechabites are the descendants of Jonadab, who, you will of course recall, ordered his followers not to touch alcohol or live in houses or grow gardens back in 2 Kings:10. And what has all that got them? Refugee status in Jerusalem.
God sends Jeremiah out to make an announcement: Rechabites rule, Israelites drool. And what is their reward? Children. Lots of children. In tents. Yay?
God orders Jeremiah to write down all the hateful things he's said about the Israelites. Then for some odd reason, because normally he loves this stuff, Jeremiah sends his follower Baruch to read the scroll.
They trick everybody into coming to Jerusalem with a fast, and then when all the commoners are assembled, Baruch reads off the screed to them. The princes are off in another part of the temple playing poker or something, but they get word of what's going on and send for Baruch. Then they make him read the whole thing out again. They get scared and tell Baruch and Jeremiah to go and hide, then take the scroll to the king.
The king burns the scroll, but have no fear! God just tells Jeremiah to write a new one. Kind of makes you appreciate thumb drives, no? And then god informs the king that he's going to punish him and his children and his slaves for that.