From Dark Comes Light

What happens if at the Battle of Hogwarts Hermione is the only one of the Golden Trio that survives? After finding the Resurrection Stone Hermione contacts Harry and he sheds some light on happiness that is soon coming her way. Harry warns Hermione to get rid of the stone so it doesn't fall into the hands of someone who would abuse its power. Just after Harry leaves footsteps are heard from the forest behind Hermione.
Is it her happiness ?? Or an old foe ??