Having Benkei back from Kumano, Yoshitsune and his troops slowly advance on the sea to Nagato, where the Heike family has fled to. On the way, Yoshitsune succeeds in winning more local navies to the Genji’s side. In Nagato, Tomomori and the rest of the Heike family are on alert but confident since sea fight is their forte, while Tokiko feels anxiety and works out a trick to protect the very young emperor. Hearing that it was Yoshiko who was on the boat holding the pole with the fan at Yashima, Yoshitsune worries about her safety. As a battle is approaching, Yoshitsune secretly writes to Yoshiko to let her know the way to protect herself from being attacked by the Genji’s army in the battle.
周囲の水軍を味方につけながら、平家のいる長門へ船を進めていた義経（滝沢秀明）は、人知れず平家軍にいる妹・能子（後藤真希）の安否を気遣い、悩みを募らせていた。一方、船戦に自信を見せる平家の中でひとり戦の行く末に不安を覚えていた時子（松坂慶子）は、ある計略を考え始める。決戦の日が近づいたある日、心中を察した弁慶（松平健）に促された義経は、能子へ、戦いに巻き込まれないよう手紙を書くのだが…。
