Dear Readers,

Once again, thank you for following us over from our first three stories! And to our new hands, welcome to the Pegasus Patronus Series! This fic series is an AU with many OCs, so DJ Vivian and I (my fic collaborator) do apologize if you get confused. We recommend starting at the very beginning of the series.

We are deep under the influence of our Muse, and after having written 24000 words in 12 days, we decided we had to continue our stories with The Fatal Mistake. Please help this story get more recognition and hits by reviewing. Thank you. And as always, enjoy!

Much Love,

Rae Carson and DJ Vivian

P.S. The Pegasus Patronus Series is as follows:

The Prophecy Renewed
A Forsaken Arising
Potter's Stolen Scion
The Fatal Mistake

CHAPTER ONE:

DARK PAST

It had been a hard night at work. Remus wearily trudged his way home from the Ministry that morning. It was difficult work, trying to get the other werewolves to cooperate with him. And this past night shift had been particularly taxing, as those involved in the current situation seemed determined to run him out yet again. They suspected his loyalties. And with good reason, thought Remus. He was now married to a prominent healer woman and secretly working for Harry and his team of Aurors on the graveyard shift.

Remus walked into the kitchen, looking forward to seeing his wife, Adonna. She always had a happy smile for him to come home to. She worked just as hard as he did—if not harder—but she was a bit traditionalist in the way she insisted on making breakfast for him. It was their customary routine to eat breakfast together before he went upstairs to sleep and she went off to St. Mungo's to work.

"Hello!" Remus called out. He hadn't seen Adonna in the kitchen. When nobody answered, he walked into the lounge. His eyes widened as he saw Adonna in a heap on the floor. She was face-down. He ran immediately to her.

"Adonna?" he questioned, full of worry. He gently picked her up off the floor and turned her around to face him.

"Adonna, sweetheart?" He put a hand on her face, attempting to wake her. She didn't respond the second time either. "Are you okay? What's wrong? Please tell me, Adonna!" Remus shook her lightly. She wasn't breathing and he couldn't hear her heartbeat.

Panic was starting to set in, as Adonna was exhibiting all the classic signs of a magical execution—namely, nothing was outwardly wrong with her, but she still appeared to be dead anyway. This isn't fair, how could I lose two wives in less than twelve years...

Remus forced himself to be rational despite the ominous sinking feeling in his chest. He sent off a Patronus to Harry, who was just coming on-shift at the Ministry.

His son-in-law was there in less than two minutes. "I saw your Patronus, Remus. What's wrong?"

"It's Adonna..."

Harry proceeded to summon some Remediables, or quick-response healers, from St. Mungo's. It quickly became apparent that it was just as Remus had originally feared. Adonna was simply dead, doubtless killed by the most horrible of all Unforgivable Curses, the Avada Kedavra.

Harry was heartbroken; he never thought he'd have to go out on a call where his own mother-in-law would have been murdered. But that's just what had happened. Remus sat there on a couch in the lounge with a blank expression, barely managing to answer anybody who questioned him. Harry had seen that look a thousand times; it was the dull-eyed stare of somebody whose loved one had just been killed. What made things worse is that Adonna had been a few weeks pregnant and not yet informed Remus. Harry didn't quite know how to break the news to the man. Remus was barely holding it together as it was. And right now, Harry felt so horrible for his father-in-law, he'd do just about anything to make things right again.

But first, he had to break the horrifying news to his wife...

Shantiel had helped to start a primary school for magical children. She tried to arrive early every morning to set up the classroom. Minverva McGonagall, along with Albus Dumbledore felt that the younger members of Wizarding families deserved the same education as the older students that attended Hogwarts. It especially made it easier for those who had children who were Metamorphmagi. They had chosen a building much like St. Mungo's in London. It had only been a couple of years, but it seemed to be going quite well. Shantiel was asked to be a teacher a year after her son, Maxwell, was born. At first she wasn't quite sure but Adonna and Harry both encouraged her to do so. She would have more time with the kids and have the same days off. She accepted the job helping the little ones. She truly enjoyed it.

Harry stood outside of the classroom door. He sighed and ran a hand over his eyes as he watched his wife hanging the pictures from her little students. Harry raised his hand and knocked on the window. Shantiel smiled in puzzlement when she saw him there. The knot in his stomach became tighter. He wished desperately that he didn't have to do this to her. This was the one thing that he dreaded the most about his job. Shan opened the door. Her smile faded as she saw his expression. Her eyes became worried.

"Harry, what is it? What's wrong?" she questioned him, the concern growing in her voice. Harry remained silent for a moment more. He knew he had to stay professional but he couldn't help it. This was family. Tears pricked the corner of his eyes. He sighed as he looked up at her.

"Mum...was killed this morning," Harry said grimly. Once again silence met them. Shantiel's eyes grew wide with fear and she covered her mouth with both hands. Harry went on, "Dad came home from work and he found her…in the lounge. No one knows who did it. They don't know why, either." The woman shook her head in disbelief. Her mum…gone? This had to be some cruel nightmare.

"No, don't say that. Who put you up to this?" Shantiel said with tears in her eyes. Harry knew that it was hard for her to wrap her mind around this. He stepped close to her and wrapped his arms around her. She finally broke down with heart-wrenching sobs. "H-how did it happen? She's so young!This can't be real! It's just not right!"

"I'm so sorry, darling," Harry said, as tears fell down her face. Adonna was his only mum, too, so he truly felt for Shantiel. "I already spoke with Minerva. Luna is going to cover for you for the next couple of weeks." Shantiel nodded numbly, letting him guide her down the corridor.

Molly entered the Potters' lounge with a tea tray. Shantiel sat on the couch with her husband and stepfather. She held on to Remus's hand in comfort. He was still dazed. This time appeared to be worse than the time his first wife had died. Adonna had been pregnant as well, which meant their baby died too. The silence filled the room. Most of them were thinking the same thoughts...what to do now? The front door opened. Abigail, now eleven, walked in with her five-year-old brother, Maxwell. He broke loose from Abby's hand and ran over to Remus.

"Papa!" The little boy squealed excitedly. Remus barely responded. Harry walked over and picked up his little boy. Shantiel sadly wiped her eyes. Now the children had to know too. Max tilted his head curiously.

"Why is everybody sad?" he asked innocently. Shantiel sighed, gesturing for Abigail to come closer.

"Something really bad happened to Nana this morning," Shantiel started. Max looked at his hands. He looked up at his parents.

"But she'll be okay, right Mummy? Max asked hopefully. Shantiel looked at him as she ran her fingers through his dark hair. She was touched by his pure innocence. She shook her head. Harry continued.

"Nana was…hurt badly by somebody," Harry finished, the grief strong in his voice. "She was hurt badly enough that she passed away."

"What's 'passed away'?" Max asked.

Abby, who was standing next to her brother, spoke up, "It means she died, Max." Then she turned to her parents in concern, "How did she die? Nana wasn't very old. Did someone kill her?"

Abigail was too intelligent for her own good. Harry shook his head and whispered in her ear, so only she could hear, "When Max isn't here, I'll tell you more, okay?"

"Okay, Daddy," she whispered in return. "I understand."

Later that day, Harry was finally able to explain to his precocious eleven-year-old that her Nana had indeed been killed by someone. She had a thousand other questions, none of which Harry felt like answering. But he did the best he could. It was a pity this had to happen just before Abigail was to go off to Hogwarts for her first year. Above all, his little girl wanted to do her best to try and help everybody be happy again.

It was a full day before Harry finally fully questioned Remus about Adonna. He knew that Remus hadn't witnessed anything, but it was important they get to the bottom of who the murderer was before the trail went cold.

"Is there anybody who you can think of that would want her dead?" asked Harry.

"Nobody I know personally," Remus said sadly, "at least not since we've been married."

"Are you certain?" Harry had been informed by Adonna's autopsy report that she had had a faded Dark Mark on her left arm. It was something he had never known about his mother-in-law. Initially, it had come as a shock, but Harry was now a practiced Auror and very little surprised him about people anymore. He was also determined to get to the bottom of things.

"Remus, how come you never told me that Adonna had a Dark Mark?" Harry quizzed him.

"Harry," Remus said with a hint of exasperation, "when you love someone, and they love you back, you don't question their past. You judge them by what they are doing in the present, and what they will do in the future."

Harry nodded, "Of course. I understand." And understand he did, for if people went by Harry's past mental connection with Lord Voldemort, he would indeed by judged as an untouchable person.

"I really don't know how or why Adonna wound up getting that Dark Mark, though, Harry," Remus said honestly. "I wish now that I would have asked her about it. She probably would have told me. But at the time, it simply wasn't important." Harry nodded, mentally adding former Death Eaters to the list of possible suspects.

"All I know about her past is that she was married once before. They had a son together. She lost both of them to a Death Eater attack one night."

"Really?" Adonna had always been so tight-lipped about anything that happened prior to her meeting Harry that he had assumed she was simply a prudish woman who rarely ever did anything wrong. But Harry knew how dangerous assumptions could be.

"Yes," Remus confirmed. "I don't know what she or her husband did for a living. I only know that watching her husband and son be killed changed her. She said it was what inspired her most to become a wizard healer."

"Do you know when she got the Mark?"

"I have no idea," Remus shrugged. "She only mentioned, repeatedly, that it was the greatest mistake of her life and that she would doubtless pay for it later." Remus sat back and mused over what he'd just said. "Perhaps this is what she meant."

"More than likely," Harry said. "And it's my job to get to the bottom of it."