Jehu continues with his divinely-commissioned-yet-bloody work.
He writes letters to the people who attend Ahab's seventy remaining sons, telling them to fight for their masters.
But these officials and attendants have seen what Jehu has already done, so they say they'll concede to his orders.
Jehu tells them to kill Ahab's sons and bring their heads to him and Jezreel.
They comply, and Jehu tells the people that they remain innocent. It was Jehu who, fulfilling God's orders, committed rebellion and destroyed his master's house.
He proceeds to kill all of Ahab's remaining relatives, associates, leaders, and priests—utterly eliminating Ahab's house.
On the way to Samaria, Jehu meets forty-two of Ahaziah's relatives and has them all captured and slaughtered.
Jehu also teams up with another commander named Jehonadab to kill the remainder of Ahab's people in Samaria.
Jehu tells the people that Ahab has served Baal, but Jehu will serve him even better. He orders them to assemble all the priests and prophets and worshippers of Baal, saying that whoever is missing will die.
(But psst—he's secretly planning on massacring all the devotees of Baal.)
All the Baal fans gather together in Baal's temple. Jehu has them make sure that none of the worshippers of God are among them.
After he officiates over a few burnt sacrifices to Baal (just for show), he has eighty of his men come in and slaughter every worshipper of Baal. They then destroy the pillar of Baal and the temple itself, turning it into a latrine that would remain into the narrator's lifetime.
Well, Nobody's Perfect
However, despite Jehu's righteousness in committing all of these, uh, mass murders, he doesn't fully walk-the-walk. He persists in the sins of Jeroboam, getting involved with golden calves and such.
Despite this, God still rewards him and promises him that his descendants will remain on the throne for another four generations.
Israel continues to deal with outside threats, which trim territory away from it. Hazael and the Arameans manage to take over territory from the Jordan eastward (places like Gilead and Bashan).
Jehu rules over Israel for twenty-eight years and then dies. His son Jehoahaz takes over.