The Sanadas are on their way to join the Tokugawa-led campaign against Uesugi when they receive news that Mitsunari [Koji Yamamoto] and Yoshitsugu [Ainosuke Kataoka] have raised an army in Osaka to topple Ieyasu [Seiyo Uchino]. At Inubushi in Shimotsuke Province, Nobushige [Masato Sakai], Nobuyuki [Yo Oizumi] and Masayuki [Masao Kusakari] engage in a heated debate over which side they should join. What decision do the three men make? Meanwhile, Kiri [Masami Nagasawa] goes to rescue Tama [Manami Hashimoto], who is being held hostage by Mitsunari.
上杉攻めのための徳川軍に従っていた真田家に大坂で三成(山本耕史)や刑部(片岡愛之助)が打倒家康(内野聖陽)のために挙兵したという報(しら)せがもたらされる。どちらに味方すべきか、信繁(堺雅人)、信幸(大泉洋)、昌幸(草刈正雄)の三人は下野国・犬伏(いぬぶし)の地で白熱した議論を戦わせる。一方、きり(長澤まさみ)は三成らの人質となっていた玉(橋本マナミ)を救出に向かう。そして、三人が下した結論とは?