On the day of the trial by combat, Jaime returns to his brother's cell. They reminisce about their dead cousin Orson Lannister and his habit of crushing beetles with rocks. Tyrion says he could never fathom the reason for their cousin's actions, a clever acknowledgment that his pending death is just as senseless. Jaime's dumbfounded by the story, if not the subtext, and the bells toll overhead signaling the start of the ritual.
Jaime wishes Tyrion good luck and leaves. The royal guards take Tyrion up to the dueling grounds where his fighter, Oberyn Martell, puts on an excellent show. The first few strikes go so well that the brothers exchange hopeful glances. But when both champions wind up dead, Tyrion's earlier confession (albeit sarcastic) leaves the council no choice but to rule in favour of death as his Jaime stands watch.