What does 1 Kings 16:9 mean?

One of Elah’s officials, Zimri, who was in charge of half the chariots, plotted against him. While Elah was getting drunk at the house of Arza, the palace manager in Tirzah, 1 Kings 16:9 - Modern Text Bible

(Zimri, a military leader, sees an opportunity when Elah is vulnerable—drunk and distracted. The setting is intimate and careless, showing Elah’s lack of caution.)