After Blackthorne survives a brazen assassination attempt, Toranaga realizes he must ferry his allies out of Osaka or risk certain defeat.

Blackthorne and Mariko test their new alliance as they train Toranaga's gun regiment for war. Yabushige must navigate his past promises to Ishido when an old friend comes to the village.

Blackthorne and Mariko struggle to contain the secret that could get them both killed. Yabushige searches for the spy who has betrayed his intentions to Lord Toranaga.

Lady Ochiba returns to Osaka in order to accelerate the Regents' campaign against Toranaga. In Ajiro, Toranaga tests Mariko's loyalty to his cause.

Outplayed by new alliances in Osaka, Toranaga is forced to carve out a new deal with a long lost family member.

Toranaga's defeated clan moves to Edo and awaits their fate. Blackthorne must decide who he fights for - the lord who has turned his back on him, or the ambition that brought him to Japan in the first place.

Mariko arrives in Osaka for the fight of her life. Blackthorne and Yabushige scramble to save their own heads as their options dwindle.

In the wake of a tragic death, Blackthorne finally considers the true nature of Toranaga's plan.