Harry Potter and the New Alliance

Yet another HP/LOTR crossover. Harry, Ron and Hermione return to Hogwarts for their 6th year. Harry is still depressed over Sirius’s death. Who is the DADA teacher? Who is this mysterious Strider and what connection does he have with Sirius? And why is Draco Malfoy acting so strange? WARNING OOTP SPOILERS! (If you have not read Harry Potter and the Order of the Phoenix you will not understand the story)