Andrew worked hard to cure his fever cases. Now that his patients were drinking only boiled water, they quickly began to get better. 'I am succeeding!' he called out in delight.

Then, one day in November, just before lunch, Denny telephoned him.

'Manson, I'd like to see you. Can you come to my house at three o'clock? It's important.'

'Very well. I'll be there.'

Andrew ate his lunch in deep thought. As he ate, Miss Page looked at him suspiciously and asked: 'Who telephoned you? It was Denny, wasn't it? I told you not to see that man. He's worthless!'

Andrew replied angrily: 'You're wrong, Miss Page! I have found him extremely helpful.'

'He's a bad doctor. He refuses to give medicines. He's so rude, too! I forbid you to see him.'

They finished their meal in silence. After lunch, Andrew walked slowly up the street towards Denny's house.

Philip greeted him with the news: 'Young Jones died this morning. And I have two new typhoid cases.'

Andrew looked down at the floor in sympathy, hardly knowing what to say.

'Don't look so pleased about it,' Denny said bitterly. 'You like to see my cases get worse, while yours get better! But if that sewer-'

'No, no!' Andrew interrupted. 'I'm sorry - honestly, I am. We must do something about the sewer. We must write to-'

'It's no use writing letters!' Philip cried. 'There's only one way to make them build a new sewer.'

'What's that?'

'Blow up the old one!'

Andrew was not sure if Denny had gone mad. 'But you're not being serious.'

Denny looked at him with scorn. 'You needn't help me, if you don't want to.'

'Oh, I'll help you,' Andrew promised.

All that afternoon, while visiting his patients, Manson wished he hadn't made the promise. Denny's plan was too risky! If they were discovered, they would both be dismissed from their posts. Andrew trembled at this thought. He was angry with Philip; swore a number of times that he would not go. But, for some reason, he could not break his promise.

At 11 o'clock that night, Denny and he set out with the dog, Hawkins. It was very dark and wet, and a strong wind blew the rain into their faces. The two men, each of whom carried explosives in his coat pockets, walked quickly along the empty streets. When they reached the sewer in Glydar Place, they broke open the lid, which had not been lifted for many years, and then shone a light inside.

'Nice, isn't it?' said Denny. 'See the holes in the wall? Look, Manson - look for the last time!'