Kekkaishi Season 1 Episode 49 Sad Demon Flower

Masamori has given an order to fill up the karasumori valley to prevent Kaguro's plan of infiltration. Meanwhile, Yoshimori and Tokine are trying to find a way to defeat Kaguro who has the power to become invisible. Tokine discovers a flower which can include Kaguro's power and give them an opportunity to hurt him. But, the flower needs a "sad" demon to bloom, and the closest one is in the maternity ward of a nearby hospital. The two Kekkaishi must risk their lives to extract the flower before Kaguro realizes their plan or the sad demon kills them.