Jin delivers a lecture at the Seitokukan in Nagasaki in order to promote penicillin. In fact, he has come all the way to Nagasaki not just to popularise penicillin, but also because he has made up his mind to see Ryoma and tell him about the assasination. However, he is not able to meet Ryoma. Just when he has half given up hope, Ryoma suddenly appears in front of him. Jin is overjoyed to finally meet Ryoma, but the Ryoma he sees is not the man he knows.
Ryoma has been obtaining weapons from Glover and making money selling them to Choshu, which is at war with the shogunate. A troubled Jin visits Choshu with Ryoma.
What he sees over there are a large number of dead and wounded among the shogun’s army. They are believed to have been shot with the guns Ryoma had sold. Ryoma had coldly watched that battle …
Darknes edges closer and closer to Ryoma. Will Jin be able to save Ryoma who has lost his bearings?
南方仁（大沢たかお）は、ペニシリンの普及のため長崎の精得館で講義をする。長崎まで来たのはペニシリンを広めるだけではなく、坂本龍馬（内野聖陽）に会い暗殺の事を伝えようと決心したためだった。だが、龍馬に会えず半ば諦めかけていたその時、突然仁の前に龍馬が現れる。ようやく龍馬に会うことが出来たと喜んだ仁であったが、そこで出会った龍馬は仁の知っている龍馬ではなかった。
南方仁為了推廣普及盤尼西林，在長崎的精得館講課。但其實仁來到長崎的另一個目的，是想當面告訴坂本龍馬，他會遭到暗殺。
但是仁一直見不到龍馬，正當感到灰心的時候，龍馬突然出現在仁的面前。仁感到非常開心，但龍馬卻似乎變了。龍馬進口武器，將武器賣給和幕府戰爭的長州，謀取利益...
