Medusa's Heir Book II: The Prisoner of Azkaban

Y/n has never been in trouble with the law, whether it's muggle or wizard law. Now everything has changed, a peaceful and safe existence was no longer possible for her. Her life was now hanging by the thread in both worlds. Pain and grief have wrapped their arms around her and refuse to let her go.
However that won't be her only worry; for twelve long years, the dread fortress of Azkaban held an infamous prisoner named Sirius Black. Convicted of killing thirteen people with a single curse, he was said to be a dedicated follower of the Dark Lord, Voldemort. Now he's escaped. And the Azkaban guards heard Black muttering in his sleep, "At Hogwarts . . . At Hogwarts." Is he coming for Harry and Y/n? The pair isn't safe, not even within the walls of their magical school, surrounded by his friends. Because on top of it all, there may be a traitor in their midst.