The remaining Israelites accuse Jeremiah of lying to them so the Babylonians can enslave them as well. A fair point that is probably true. So they go to Egypt against prophetic advice.
When they get there, god tells Jeremiah to bury some stones and tell the Israelites they'll be the Babylonian king's pavilion when he arrives, an occasion which will be marked by smiting and burning.
The Israelites, having cleared their sins with god, are now committing new ones. Specifically the wives appear to be worshipping someone called the Queen of Heaven and the husbands aren't stopping them. The punishment? Death, famine, cursing. And so begins a new cycle.
Jeremiah tells Baruch, who wrote his words down a few chapters ago, to seek an ascetic life.