How does Juvenal meet Iridia in "Juvenal Nyx"? What impact does this encounter have on him?

Juvenal spends several days on the roof at night, eavesdropping on his friends and during the day he falls into a coma like state. On the fourth day, he feeds. Twenty-three years pass and during that time, he lives in the underground chamber Julia gave him, learning about the limitations of his new life.