The Dementors vs. Hogwarts
Harry Potter and the Prisoner of AzkabanThe conflict between the Ministry's decision to station Dementors at Hogwarts and Dumbledore's resistance, culminating in the Dementors' removal.
increasing
Bearing strength in each event
decreasing
Dementors guard the school

The Unwelcome Guests
The Ministry's Order
After Sirius Black's escape, the Ministry of Magic stations Dementors at all entrances to Hogwarts. They are meant to protect the students, but they create a gloomy atmosphere. Dumbledore is unhappy with their presence.
The Impact on Students
The Dementors affect everyone, especially Harry. They cause him to faint and hear his mother's screams. Other students feel depressed and cold. The school's morale drops.
Dumbledore's Stance
Dumbledore refuses to allow Dementors inside the castle. He limits their patrols to the grounds. This creates tension with the Ministry, but Dumbledore is firm.
Dementors removed

The Aftermath
The Failed Kiss
After the Shrieking Shack events, the Dementors attempt to perform the Kiss on Sirius and Harry. They nearly succeed, but Harry's Patronus drives them away. The incident reveals that the Dementors are out of control.
Fudge's Decision
Cornelius Fudge, realizing the Dementors nearly kissed an innocent boy, orders them back to Azkaban. He admits they are too dangerous. The Dementors are removed from Hogwarts.
The Relief
Students and staff are relieved. The castle becomes brighter. The threat of the Dementors is gone, but the memory of their horror remains.
Start of term to end of year
End of the school year