A code enforcement case begins with a piece of paper taped to a door and can end with a lien larger than the house is worth. This article explains how the system actually works: who the inspector is, where the authority comes from, what a notice of violation is and is not, and why the deadlines on it are the most important thing on the page. It covers the constitutional limits on inspections after Camara and See, the due process required before a fine becomes a lien, the excessive fines problem that Timbs made available in every state court, and the vagueness challenge that occasionally works. It explains daily-accruing penalties, abatement and demolition, receiverships, and the difference between a criminal citation and an administrative one. It also treats the enforcement side honestly, including the tenant habitability cases where enforcement is the only remedy that works. Two properties are followed from first notice to resolution.