The Hogwarts | Walkthrough Harry Potter OP Guide

Ron will suggest you to go to Snape's classroom for another occlumency lesson. The rules haven't changed.

Hermione proposes to go to the Room of Requirement, where entire Dumbledore's Army awaits. Teach them how to cast Expecto Patronum. A few seconds later...

...Malfoy and his pals will break into the room. You must beat them one versus five. :) Even if you win (don't know if this is possible), it won't change a thing. You lost. :)

The next step is going to Hagrid's hut. Malfoy is already there. When you get close, fight will begin.

This time you can win, although result of fight doesn't make much difference again. A few new tasks will appear on your map.