Harry Potter-Granger and the Elixir of Life

One day, Mr and Mrs Granger find a young boy set on their doorstep and adopt him. Ten years later, their children, Harry and Hermione, embark on their first year at their new school, Hogwarts, a school for young witches and wizards, unaware of what adventure lies in store for them. / AU re-telling of "Philosopher's Stone".