2 Chronicles 23:13

13 She looked, and there was the king, standing by his pillar at the entrance. The officers and the trumpeters were beside the king, and all the people of the land were rejoicing and blowing trumpets, and singers with musical instruments were leading the praises. Then Athaliah tore her robes and shouted, "Treason! Treason!"

She–Athaliah (queen mother/regent)
the king–

This section of God's Word reads like a soap opera. To get a little background to today's verse, go back a chapter and read 2 Chron. 22:10-12.

Athaliah and Joash

10 When Athaliah the mother of Ahaziah saw that her son was dead, she proceeded to destroy the whole royal family of the house of Judah. 11 But Jehosheba, the daughter of King Jehoram, took Joash son of Ahaziah and stole him away from among the royal princes who were about to be murdered and put him and his nurse in a bedroom. Because Jehosheba, the daughter of King Jehoram and wife of the priest Jehoiada, was Ahaziah's sister, she hid the child from Athaliah so she could not kill him. 12 He remained hidden with them at the temple of God for six years while Athaliah ruled the land.