Shishigatani Conspiracy (鹿ヶ谷の陰謀) - S1.E42

Kiyomori receives secret information that the cloistered Emperor Go-Shirakawa and his aides, including Narichika and Saiko, are plotting to overthrow the Taira family. Kiyomori bursts in anger and captures Saiko to extort a confession out of him. Saiko, however, outrages Kiyomori by saying things that rub Kiyomori the wrong way, and Kiyomori orders for the execution of Saiko. Narichika is also captured and killed off by Kiyomori, despite Shigemori's desperate plea for Narichika's life. Witnessing Kiyomori's mercilessness to those who stand in the way, Shigemori becomes fearful of Kiyomori.