It follows Harry Potter's struggles through his fifth year at Hogwarts School of Witchcraft and Wizardry, including the surreptitious return of the antagonist Lord Voldemort, O.W.L.

During the summer, Harry is frustrated by the lack of communication from his friends and by Dumbledore's refusal to let him help in the struggle against Lord Voldemort.

Later, members of the Order of the Phoenix arrive at the Dursley residence and take Harry to Number 12, Grimmauld Place.

Number 12 is Sirius Black's family home and the headquarters of the Order, which is a secret organisation founded by Dumbledore to fight Voldemort and his Death Eaters.

Under the leadership of Cornelius Fudge, the Ministry of Magic is waging a smear campaign against Harry and Dumbledore, claiming they are lying about the return of Voldemort.

Harry faces legal charges for the Patronus Charm he performed, but is exonerated and returns to Hogwarts.

Lucius Malfoy reveals that Harry was lured to the Ministry by a false vision from Voldemort, who wishes to hear the prophecy contained in the sphere.

Back at Hogwarts, Dumbledore tells Harry the prophecy was made by Professor Trelawney, who predicted the birth of a child with the power to vanquish Voldemort.

Harry feels overwhelmed by the prophecy and the loss of Sirius, but the wizarding community now believes him and respects him.

[11] The New York Times writer John Leonard praised the novel, saying "The Order of the Phoenix starts slow, gathers speed and then skateboards, with somersaults, to its furious conclusion....As Harry gets older, Rowling gets better.

[2] The first book in the series, Harry Potter and the Philosopher's Stone, was first published by Bloomsbury in 1997 with an initial print-run of 500 copies in hardback, 300 of which were distributed to libraries.

[14][15] The fourth novel, Harry Potter and the Goblet of Fire, was published 8 July 2000, simultaneously by Bloomsbury and Scholastic.

[16] The fifth novel, Harry Potter and the Order of the Phoenix, is the longest book in the series, yet it is the second-shortest film at 2 hours 18 minutes.

[18] In 2007, Harry Potter and the Order of the Phoenix was released in a film version directed by David Yates and written by Michael Goldenberg.

The English-language version has topped the bestseller list in France, whereas in Germany and the Netherlands, an unofficial distributed translation process was started on the internet.