THE STORY OF SEJANUS PLINTH AND HOW CORIOLANUS SNOW BETRAYED HIM 

In "Ballad of Songbirds and Snakes", Sejanus Plinth is one of the main characters. He is a classmate of Coriolanus Snow, who later becomes President Snow in the original trilogy.
Sejanus comes from an upper-class Capitol family, but unlike many of his peers, he shows sympathy for the inhabitants of the districts and questions the injustices of the Hunger Games system. Throughout the story, Sejanus engages in activities that challenge the Capitol's rules and seeks ways to help the districts' tributes.
His relationship with Coriolanus Snow, the protagonist of the prequel, is complex and develops throughout the plot. The story of Sejanus Plinth is an important element in "The Ballad of Songbirds and Snakes," which explores the origins of many elements that would later become integral parts of the original "Hunger Games" trilogy.