Sannan has been using materials left behind by Kodo to continue to try to improve the medicine in secret. He drinks the medicine and transforms into something which is no longer human. After seeing the wound Sannan infected on Chizuru heal in an instant, Hijikata asks her if she's a rasetsu, but...
Later, the commotion over Sannan adds to the decision to move the Shinsengumi headquarters to Nishi Hongwanji. Chizuru continues to search for her father, but she is unable to find any clues to his whereabouts. Then one day, Chizuru happens to overhear Okita's secret.
You're right. The truth is, 
medicine like this should not be used.
معك حقّ. الحقيقة هي أنّ دواء
كهذا لا ينبغي استخدامه
In der Tat. Die Wahrheit ist,
dass die Medizin nicht angewendet werden sollte.
Ciertamente.
Esta medicina no debería usarse.
Desde luego.
Esta medicina no debería usarse.
Vous avez raison.
Hai ragione. Medicine come questa 
non dovrebbero mai essere usate.
É verdade. Um remédio
destes não deveria ser usado.
Ты прав. Такой препарат
нельзя применять налево и направо.