Muff and Jeff are two guardlike characters who have been taught to obey certain rules when they are going out to the "alarms". Gradually they forget the rules as defenders of the law and order and become criminals themselves.
There are some vague reasons for this development. Especially Muff tells, first, how there was a boy at school who was dimissed for telling a story of a violent killing of an old woman. In the next phase, Muff tells Jeff that actually he was the boy who told the brutal story and who got dismissed. At the end Muff's only comment about the incident is that "they never should have put me to school".
At the end of the play Jeff feels remorse but Muff rejoices in passing the gate from good to evil.