Night Watch is a fantasy novel by British writer Terry Pratchett, the 29th book in …
‘You took an oath to uphold the law and defend the citizens without fear or favour,’ said Vimes. ‘And to protect the innocent. That’s all they put in. Maybe they thought those were the important things. Nothing in there about orders, even from me. You’re an officer of the law, not a soldier of the government.’
— Night Watch (Discworld, #29; City Watch, #6) by Terry Pratchett (Page 218)