Here is a quick overview of the five books:
Gods and Kings (Chronicles of the Kings #1) - The story of King Ahaz (the father of Hezekiah) and how his reign leaves Judah devastated because of his idol worship. The book closes with Hezekiah getting married and becoming king.
Song of Redemption (Chronicles of the Kings #2) - The beginning of Hezekiah's reign and how he seeks to follow God's Laws unlike his father.
The Strength of His Hand (Chronicles of the Kings #3) - God rewards Hezekiah for his faithfulness. His wife, though, resorts to idolatry because she is barren. The Assyrians are approaching which causes more stress for the king.
Faith of My Fathers (Chronicles of the Kings #4) - Hezekiah's death brings his son, Manasseh, to the throne.
Among the Gods (Chronicles of the Kings #5) - A remnant of Jews flee to Egypt to escape King Manasseh's tyranny.