Time passes … Now under the supervision of the Satsuma domain, Ryoma sets up a maritime shipping company called Kameyama Shachu with his buddies. He also meets Nakaoka Shintaro, a fellow Tosa samurai who has left the domain and is under the supervision of the Choshu domain, and they hit it off. The two of them run around with their sights set on a reconciliation between the Choshu and Satsuma domains.
One day, Taki visits Jin who is searching for a way to make powdered penicillin. The shogunate has expressed a desire for Jin to treat Ehime, the wife of the feudal lord of Kawagoe domain, for a lump. Jin accepts the request and heads for Kawagoe with Saki. They stop by at an inn along the way and encounter a girl called Ohatsu. In that moment when Jin comes into contact with Ohatsu, he has a strange sensation as if electricity were running through him …
Upon their arrival at Kawagoe, Jin tries to treat Ehime immediately, but is rejected by her. “Treatment is no use,” she tells him. After that, they manage to gain her acceptance after some persuasion from Saki. But, in the end, it is determined that because Ehime’s lump is benign, it can be removed with surgery. However, there is a possibility that the anemic Ehime will die from blood loss …!?
ペニシリンの粉末化を模索している仁（大沢たかお）の元へ多紀（相島一之）がやって来る。川越藩主の妻・恵姫（緒川たまき）のコブを治療してほしいと言うのだが…。
坂本龍馬和同伴們成立了「龜山社中」，並結識了同為土佐脫藩浪人的中岡慎太郎，一拍即合。兩人為了長州和薩摩的和解，而四處奔走。
南方仁正在摸索如何將盤尼西林粉末化，就在此時，幕府方面希望仁能治療川越藩主之妻-惠姬的腫瘤。於是仁與小咲動身前往川越藩，但惠姬卻拒絕治療...
