Roses in December

The battle is over and Voldemort is dead but not all the Death Eaters are vanquished or captured. Harry is on his way to return the Elder Wand to Dumbledore's tomb, when he is called back to the castle. No one other than the chosen one appears to know that Hermione is in grave danger, that her life, the very existance of the girl he secretly loves more than any other is about to be blasted into oblivion. One silly little spell has changed everything, is it possible for Harry to put it right and what will be the consequenses for them both?