A school girl visits the nurses office, and while the girl is speaking, the nurse is silently pouring chloroform onto a rag. The nurse then chloroforms the school girl.
In one panel, the nurse looks incredulously at the cloth and probably mutters, "wow, that worked!"
The girl wakes up tied to a bed and gagged.
Alternate title: [Sakaguchi Shizuka] Kinbaku no Tenshi
Source: exhentai.org