2 Kings 1:16-20

Elijah told the king, “This is what the Lord says: ‘Is it because there's no God in Israel for you to consult that you have sent messengers to ask advice of Baal-zebub, the god of Ekron? As a result you will not leave the bed on which you are lying. You're definitely going to die.”

Ahaziah died just as the Lord had said through Elijah. Because he had no son, Joram succeeded him as king in the second year of the reign of Jehoram, son of Jehoshaphat, king of Judah.

The rest of what happened in Ahaziah's reign and what he did are recorded in the Book of Chronicles of the Kings of Israel.