Jaime Lannister arrives in Tyrion's cell and per his father's orders, chains his brother's hands. Tyrion is escorted to the throne room where a large audience awaits for his trial. King Tommen recuses himself and introduces the judges: Tywin Lannister, Mace Tyrell and Oberyn Martell. Tywin presides over the event and calls the crown's witnesses.
Kingsguard knight Meryn Trant takes the stand first and recalls Tyrion's threats against Joffrey. Tyrion counters that the king was terrorizing Sansa Stark, but Tywin orders him to remain silent.
Grand Maester Pycelle reveals that potions were pilfered from his supplies, including "The Strangler," a rare and deadly poison used to kill the king. The maester produces Sansa's necklace, recovered from Dontos Hollard's body, and explains that he found Strangler residue inside a gem setting.
Cersei recounts how Tyrion tried to put Joffrey on the front lines during the Battle of Blackwater and once threatened, "Your joy will turn to ashes in your mouth, and you will know the debt is paid." When Oberyn asks about the debt in question, Cersei explains Tyrion was angry when she reminded him to keep his whores away from Red Keep.
Varys recalls Tyrion's bad behavior during a Small Council meeting, and suggests the accused became sympathetic to the northern cause after his marriage to Sansa. Tyrion is permitted to address Varys and reminds the eunuch that he saved the city. Varys assures him that he has not forgotten.