THIS STORY WILL BE EDITED AND RE-UPLOADED TO MY NEW ACCOUNT. SEE THE NEWEST CHAPTER FOR DETAILS. Voldemort had another Horcrux. Nineteen years later he returned. In 2047, Harry Potter and Luna Lovegood, the two remaining human beings on Earth send sixty minutes of memories each to their younger selves. Not really time travel but definitely AU.
It's 2011 and Luna finds a way to jump across universes and go back in time. Plans are made to retrieve dead friends and family and bring them back to the 'proper' universe. When there they read the Harry Potter books.