The Trio and the Order of the Phoenix

Part 3 of the Trio Series. Voldemort has returned and Dumbledore has reformed the Order. After a summer living in a dreary safe house, our trio return to school. Dark forces outside the castle plot Harry's downfall, but unfortunately the new DADA teacher has her own agenda. Can the trio boot her out on her backside before she takes over? I don't own Harry Potter. R/Hr.