Three ways this alternate-universe story is different from canon—
1) When Dumbledore appears before the Granger family at the beginning of summer 1995, and wants to take Hermione to a place where she is "safe" (meaning, Grimmauld Place), the parental Grangers refuse permission.
2) Luna Lovegood gets a Seer vision about Harry and Dudley being attacked by Dementors; and Luna acts on her Seer vision in a way that helps Harry. (Also, Harry rescued Luna from Ravenclaw bullies in fourth year, not fifth year.)
3) On the day that Harry and Dudley are attacked by Dementors, Tonks gets a "hunch" (low-power Seer vision) that Mundungus Fletcher has skived off guarding the Privet Drive house. Tonks Apparates to the house, finds it unguarded and begins guarding it. As her hunch did not tell her that Harry has left the house, she is not at the playground when Harry is attacked there. It is possible that the same thing happened in canon, and that when Harry and Dudley returned to the Privet Drive house in Chapter 2 of OOTP, that invisible Tonks was standing nearby and was watching events unfold without Harry knowing she was there.
This story contains bashing of Albus, Molly, Ron and Ginny. If this is not your sort of story, stop reading now.
No Trip to Sweden
Saturday, 1st July 1995, evening
The end of the Hogwarts term
Platform 9¾, King's Cross station
Once all three Hogwarts students were off the train, Luna Lovegood gave a hug to her friend Harry Potter, and to her friend's friend Hermione Granger. Hermione Granger looked surprised when Luna hugged her.
Then Luna hurried to pull her trunk to where her father, Xenophilius Lovegood, was standing.
At which time, Luna let go of the handle of her trunk so that she could give a fierce hug to her father. Who just as fiercely hugged Luna back.
"My Moonbeam has returned," he said happily.
It was said often in Wizarding Britain that "Purebloods don't hug." Nonetheless, father and daughter hugged right there on the magical train platform, despite the frowns of Lucius and Narcissa Malfoy, who were standing nearby.
When the hugs ended, Xenophilius asked Luna, "Would you like to eat dinner in the Rookery, in Diagon Alley or in Sweden?" The Lovegoods had made plans to spend Luna's summer holidays in Sweden, seeking the elusive Crumple-Horned Snorkack.
Now Luna sighed, as she looked her father in the eyes. "Daddy, I can't go to Sweden this summer. Harry Potter will need me here."
"Harry Potter, he rescued you from those Ravenclaw bully girls, right?"
Luna beamed. "He did. Then he told me that I was a friend."
"Friends always are nice to have." Xenophilius hugged his daughter again. "Meanwhile, this summer, what does Harry Potter need you here for?"
"He needs me to watch him fight off an attack next month."
Xenophilius looked alarmed. "Does he want you to fight alongside him? You're underage to do magic outside of Hogwarts."
"Don't worry, Daddy, I'll only watch the fight, not myself fight. As for Harry Potter, he doesn't 'want' anything from me, because he doesn't know he has a fight in his future. But he's definitely going to need me, and soon. I've Seen it."