This picks up at chapter 20 in the Prisoner of Azkaban: the Dementors kiss.
On pages 381 and 382 of the hard back.
"Moony, please listen to me. Please?" Sirius begged taking a step towards the werewolf. "It's me Padfoot, your mate… remember?"
The werewolf stilled as he took in the older human. This grown man could not be his mate. His mate along with his two best friends were long gone.
Had been for over twelve years! This human was lying to him!
Rage took over and Moony crouched into a stance and gave a growl that made the smaller humans cower in fear and tuck into each other.
Like they should.
Then suddenly out of nowhere a dog appeared where the meddling and lying human had been standing.
This dog was achingly familiar. He looked like his mate, sounded like his mate, and smelled like his mate.
But Padfoot was GONE!
"Moony, please…" the dog thought to the werewolf desperately. "Please, please remember me. I couldn't go on with Remus if Moony forgotten me." He thought desperately.
"You are not my mate. My mate is gone." Moony replied simply before rounding on the younger humans.
"Moony! I was taken from you!" the dog cried out suddenly. Moony thought for a moment. It was possible and quite plausible.
"Prove it!" Moony growled still crouched in his attack stance.
"I've been gone from you for twelve years. Since the full moon at Halloween. So have Prongs, Lily and Wormtail. Prongs and Lily were murdered. Wormtail was behind it. See that small dark haired boy? That is Staggers. Lily and Prongs died for him."
Moony had forgotten about Lily and Staggers.
"Wormtail betrayed us all. He had Lily and Prongs murdered and Staggers was nearly murdered as well then had me blamed for it. Please moony. Look at the boy. He looks identical to Prongs' human form James. James with Lily's eyes." The dog whined at Moony frantically.
"Staggers…" Moony whispered softly as he rose out of his crouch slowly.
"Yes!" the dog cheered as it chased its tail around once.
"Who are the other two?" Moony asked curiously eyeing the bushy haired girl and the redheaded boy.
"His Prongs and Lily." The dog explained with a bark of laughter.
Moony moved closer to the trio and the girl clung to the two boys as the red head whimpered and shrunk back.
"They are… afraid of me…" Moony said sadly.
"They still think you want to eat them… silly Moony."
"Do not call me silly. And shift back and tell them differently!" moony commanded.
The dog scoffed and mumbled before doing as he was told.
"Moony understands now. Harry he wants to meet you."
"Lupin already knows Harry!" the red head cried fearfully.
"Honestly Ronald." The bushy haired girl said pulling his hands off of her arm. "Professor Lupin and Moony are two completely different beings. Moony probably wants to see if Harry really is the baby he can vaguely remember." The girl explained like it was obvious and to Moony it was.
Harry pried the red heads fingers off of his arm before taking a tentive step forward.
"Moony it might serve you better if you… well if you sit."
Moony sat back on his haunches without hesitation. Harry took the last few steps between them before raising his hand to Moony's snout and leaving it there for him to smell. And smell it Moony did.
This was his staggers! Minus the baby smell and with a bit of earth mixed in along with two other distinctive smells and Moony knew they belonged to the other two standing just a bit away.
Quickly before anyone could register what he was doing Moony licked Harry's face.
"Ew… Moons that's gross!" was all Harry said before smiling and launching at the werewolf and hugging him tightly. The redhead whimpered loudly.
Moony was too shocked to move. This boy a mere boy of thirteen was hugging him… a monster…
"You and Sirius are all I have left. I love you moony." The boy whispered softly into Moony's ear where only the werewolf could hear.
Suddenly the boy pulled away.
"We need to find Peter." He said with such finality that the bushy haired girl pulled out a gold chain and fingered it thoughtfully.
"There is a way… what way did Scabbers run off in?" she asked.
The red head pointed southwest. The girl nodded before sitting the red head on the rock that was just to the right of him.
"Ron you'll have to stay here. Harry and I will only be a moment." She said before walking over to Moony and Harry and wrapping the chair around his neck and twisting something.
With in a blink of an eye they disappeared.
Moony heard a loud rustle and two people running this direction.
Crouching Moony protectively placed himself in front of the red head and his mate.
Two figures broke out of the bushes and confused moony and the red head.
It was Harry and the girl.
"Got him!" the girl cried triumphantly, holding up the stunned rat that triggered a memory in Moony.
Sirius turned to moony after freezing the willow.
"We need to get back to the shack Moony." He said softly with his lopsided grin. Moony huffed but led the way through the tunnel.
Sirius turned to Harry.
"take him up to the castle and to old McGonagall. She'll know what to do with him from there. tell her he is an Animagus. I'll keep an eye on moony and help him back in the morning. I'll see you then." He said hugging Harry and smiling at the other two before making his way through the tunnel.
"Merlin's beard Hermione... you are the only girl I know willing to touch a rat." Ron said in awe.
"Honestly Ronald. They'd much rather hold the rat if they sat the man he turned into as well…" Hermione said shaking her head as they made their way to the castle. Potions professor still unconscious and completely forgotten on the ground.