The next morning, xiaoli tells the captain and doctor that they have finished their research on a new drug to get rid of the worms. He wants to test the new drug on the soldiers' brains to see if it works. The captain says that he doesn't want his neighbor to become his wife's stepfather, so he wants the doctor to promise to take care of him if something happens. The doctor says that it's a brain operation and that it would take too long for him to recover. Worried that he's going to get sick, he asks the captain to promise that he won't take after his wife if something does happen to him. He also wants to know why they didn't just take off the doctor's mask and open his brain. The Captain says that they're not going to the battlefield and that they don't really need to take off his mask. He tells the doctor that he can just apply the drug to his ears and the worms will be sucked out of his ears. After the doctor has applied the drug, he feels something crawling in his head. He swears to everyone in the camp that the worm has been sucked out. The next day, all the soldiers praise the doctor, and the captain wants his sister to marry him. Everyone praises the doctor as well. He says that if he had to choose a different doctor, he'd still choose the one who did the brain operation.