The author has chosen four main points from Harry's Fifth Year to point out.

1 - Umbridge

Upon the discovery that Hogwarts' DADA teacher was actually a wanted-and escaped- criminal, the Ministry decided to place one of its own in the post, Madam Undersecretary Dolores Umbridge, who would later return to the Ministry as Head of the Muggle-Born Registration Commission. Potter and friends were outraged by the non-tactile approach that Umbridge brought, so they formed their own club (unauthorized) to teach friends actual spells they would need.

Hermione Weasley on Dumbledore's Army

"Well, I saw reason in it, if no-one else did. We actually learned good defensive spells, like the Patronus and Disarming Charms."

2 - Dumbledore's Army
Dumbledore's Army, a sort of Anti-Umbridge Defense Against the Dark Arts orgnization was assembled in the winter of 1994-1995. Among the spells practiced were the Patronus and Disarming Charms, as well as the equally useful Stunning Jinx and Reducting Charm. These spells would come into great usage later that year. However, meetings stopped when one of their own, Marietta Edgecomb of Ravenclaw House, ratted them out to the Tyrant Umbridge.

3 - The Ministry Takes Over Hogwarts

Following the observance of many "errors in standards" at Hogwarts, Umbridge appointed herself as Hogwarts High Inquisitor, which gives her certain powers. After the discovery of Dumbledore's Army, Albus Dumbledore was ousted from the school, and Umbridge took full control of the school. The situation is explained by two different members of Hogwarts faculty.

Argus Filch, Caretaker, on Headmistress Umbridge

"Well, she was the best [EXPLICIT] thing to ever happen to this school, I'll tell you that. The rules she put in perfectly fit my needs for the school. It was like she was buttering me up for something. Course, it all fell apart after she left. Blimey, that was a sad day for me."

Filius Flitwick, Charms Master and Ravenclaw Head of House, on Headmistress Umbridge

"She was absolutely revolting. The things she did to students were outrageous. Blood Quills which wrote with the writers' own blood, Potter's still got the scar from it 'I must not tell lies"...I was there personally at her trial and sentencing in front of the entire Wizengamot. Seventy life sentences, you should have seen how much Hogwarts students celebrated that day..."

4 - The Battle of the Veil

Also known as the Battle of the Department of Mysteries, this involved many members of Dumbledore's Army, as well as members of a reunited Order of the Phoenix, against members of the Death Eaters. Among the participants from each organization were (Casualties are marked with an asterisk, *)

Dumbledore's Army

Luna Lovegood

Neville Longbottom

Harry Potter

Hermione Granger

Ron + Ginny Weasley

The Order

Alastor Moody

Nymphadora Tonks

Remus Lupin

Sirius Black*

Albus Dumbledore

Kingsley Shacklebolt

Death Eaters

Antonin Dolohov

Thorfinn Rowle

Mikhail Travers

Lucius Malfoy

Bellatrix Lestrange

The Dark Lord

The battle resulted in the Resignation of Minister for Magic Cornelius Fudge and the death of wrongly convicted criminal Sirius Black.

These events proved very traumatic for Harry, and it would show in later years.