What does 2 Kings 9:14-26 mean?

Thus Jehu the son of Jehoshaphat the son of Nimshi conspired against Joram. (Now Joram with all Israel had been on guard at Ramoth-gilead against Hazael king of Syria, but King Joram had returned to be healed in Jezreel of the wounds that the Syrians had given him, when he fought with Hazael king of Syria.) So Jehu said, “If this is your decision, then let no one slip out of the city to go and tell the news in Jezreel.” Then Jehu mounted his chariot and went to Jezreel, for Joram lay there. And Ahaziah king of Judah had come down to visit Joram. Now the watchman was standing on the tower in Jezreel, and he saw the company of Jehu as he came and said, “I see a company.” And Joram said, “Take a horseman and send to meet them, and let him say, ‘Is it peace?’” So a man on horseback went to meet him and said, “Thus says the king, ‘Is it peace?’” And Jehu said, “What do you have to do with peace? Turn around and ride behind me.” And the watchman reported, saying, “The messenger reached them, but he is not coming back.” Then he sent out a second horseman, who came to them and said, “Thus the king has said, ‘Is it peace?’” And Jehu answered, “What do you have to do with peace? Turn around and ride behind me.” Again the watchman reported, “He reached them, but he is not coming back. And the driving is like the driving of Jehu the son of Nimshi, for he drives furiously.” Joram said, “Make ready.” And they made ready his chariot. Then Joram king of Israel and Ahaziah king of Judah set out, each in his chariot, and went to meet Jehu, and met him at the property of Naboth the Jezreelite. And when Joram saw Jehu, he said, “Is it peace, Jehu?” He answered, “What peace can there be, so long as the whorings and the sorceries of your mother Jezebel are so many?” Then Joram reined about and fled, saying to Ahaziah, “Treachery, O Ahaziah!” And Jehu drew his bow with his full strength, and shot Joram between the shoulders, so that the arrow pierced his heart, and he sank in his chariot. Jehu said to Bidkar his aide, “Take him up and throw him on the plot of ground belonging to Naboth the Jezreelite. For remember, when you and I rode side by side behind Ahab his father, how the LORD made this pronouncement against him: ‘As surely as I saw yesterday the blood of Naboth and the blood of his sons—declares the LORD—I will repay you on this plot of ground.’ Now therefore take him up and throw him on the plot of ground, in accordance with the word of the LORD.”