The Day of Flicker - S2.E14

Aria and Niche final make it to Houdai's house. Aria tries to hand over the letter right away, but is injured when Houdai suddenly attacks her. But Aria doesn't flinch, and tries to convince him by talking about how a person dear to her lost something important on the Day of Flicker. Houdai hears this, lets them into his house, and begins to tell the story of his memories of the incident that happened on board that airship. At around the same time, Dr. Thunderland is treating Lag and Gauche, and the unthinkable occurs...