The an donuts that Jin and Saki had presented to Princess Kazunomiya are suspected to be laced with arsenic and they are put into the Kodenmacho jailhouse on charges of attempted poisoning. Jin, who is sent to the great jailroom, is subjected to unrelenting treatment by the head of a prisoner’s group and his underlings. What awaits Jin next is brutal physical torture by government officials. Jin eventually resigns himself to death and to face Heaven’s judgment. Meanwhile, Katsu, Ryoma and Kyotaro enlist Shinmon Tatsugoro’s cooperation and attempt to intercede with the shogunate to rescue Jin, but …
In addition, Jinyudo, which has learnt of Jin’s arrest, is in utter chaos. Believing that this is the fault of the Institute of Western Medicine, Saburi blames Fukuda Genko who hails from the institute. Fukuda desperately pleads with Taki, who has been put in charge of the investigation of this case, to conduct a fair probe. However, he disregards these wishes, and decides on the death sentence for Jin, who is sent to the magistrate’s office …
南方仁（大沢たかお）と橘咲（綾瀬はるか）は、皇女和宮（黒川智花）に献上した安道名津（あんドーナツ）に毒を盛った疑いを掛けられる。捕えれた仁は、牢名主（宇梶剛士）とその手下たちから、執拗（しつよう）なまでの仕打ちを受けてしまう。“天の裁きが下ったのだ”と、仁はついに死を覚悟する。
南方仁因為獻給皇女和宮的「安道名津」，可能參有砒霜，而被關進大牢，並受到嚴刑拷打。
勝海舟、坂本龍馬、橘恭太郎等人，請新門辰五郎協助，四處奔走希望能救出仁。
而「仁友堂」的成員得知仁遭到逮捕，也陷入混亂，佐分利祐輔認為一切都是醫學館造成的，而責怪醫學館出身的福田玄孝。福田則拼命懇求醫學館的督事能夠公正調查，但是...
