A/N 3/12/2021 Edited chapter, adding more info as I felt that some of it was unclear and didn't make very much sense.

A/N Still do not own the X-men or the Harry Potter series.

Prologue

Nathaniel Essex the man better known as Mister Sinister studied the request he had received. The request was from one of his IVF clinics in Britain, specifically in Surrey. The message was from one Lily Potter nee Evans and presented an interesting opportunity. Nathaniel Essex was a scientist at heart and many years ago he had discovered the magical world and it intrigued him. He had never gotten the chance to collect a sample of magical DNA. However, he had experimented with mutant DNA which led to his discovery of the X-gene. Once he had discovered this gene, he opened several clinics and orphanages with the purpose to collect mutant DNA and if he was lucky, Magical DNA. This introduced him to the Summers family and through them he discovered the Grey family.

He had tried creating a clone by mixing Jean Grey and Scott Summers DNA, two mutants that if he was correct would create one of the most powerful mutants in existence. His goal was to create the perfect mutant, one who could remove the threat of Apocalypse, a mutant from the time of the pharaohs who was said to be a god. His first clone was a failure, and the strands of DNA would not combine correctly causing instability, so he destroyed it. With the message from Lily Potter, he had the opportunity to collect a sample of a magical DNA. If he could isolate and incorporate the X-gene with a Magical's DNA he could ensure that it would combine correctly. If he were successful, he could create an extremely powerful individual, hopefully they would have enough power to kill Apocalypse, and if he were successful, he could also incorporate some into his DNA as well.

One Month Later:

Nathaniel Essex was intrigued when he met the Potters. Mr. Potter was dead giveaway, he just looked too uncomfortable in the clinic and gawked at several of the basic machines with poorly disguised surprise clearly the magical did not get out much. Mrs. Potter however was the biggest surprise, crimson hair, and emerald eyes. Her resemblance to Jean Grey was uncanny and he wondered if maybe they might be related. Only a comprehensive DNA test would tell for sure.

"Good afternoon Mr. and Mrs. Potter. I am Doctor Nathaniel Essex, the owner of this clinic." He said as he stood to greet them, shaking their hands. "Please have a seat and we can begin discussions."

"Thank you very much for this opportunity Dr. Essex." Said Lily nervously "To be honest you are our last hope with this treatment."

"Please call me Nathan," he replied "There is no thanks necessary as I am only interested in helping people. Especially considering your unique family and circumstances."

"How do you know about my family?" James asked as he stood with his wand appearing in is hand.

"Please be at ease, I know about the magical world because I have family who are magical." He said quickly, "I still have some contact with them in the magical world so you can speak freely in here."

James and Lily both slumped in relief, making Mr. Sinister chuckle. James' wand disappeared into his sleeve and he sat back down.

"Now what is the issue? I assume you are having trouble conceiving. I apologize for the bluntness, but I prefer to cut to the heart of the matter." He asked.

"It's alright, it's actually a relief. The people who know we are having trouble treat us like were going to explode" James waved his apology away with a wry smile "We believe that I am the one who is infertile, but we are uncertain what the cause was. I believe it was a curse I was hit with in my 7th year of school."

"That is actually better than I hoped for," Essex said; "I was worried that Mrs. Potter would be infertile, if that were the case then you would need a surrogate. This is good news as it means that you will be able to carry the baby to term yourself."

Both Potters sighed in relief at hearing this but, the smile on Lily Potter's face would light up the room. He could already see their happiness as they began to become excited imagining the future they would have.

"Now to get down to business. For us to proceed I will need several things." He turned to Mr. Potter. "I am going to need a sample of your emissions, or for the harder route I will need a blood sample."

"That is a relief," James sighed, "I was worried when Lily told me that I would have to give blood what it would be used for. As for the other I would prefer to give blood."

"If that is your wish then it will take slightly longer." He stated. "Don't worry about the blood, it will remain confidential and once the process is finished and successful, I will destroy all samples. You have nothing to worry about."

"Next Mrs. Potter I will have to take a sample of your blood as well and I will have to perform a procedure to collect a few of your ovaries for the fertilization process."

Mrs. Potter looked a little uncomfortable when her said that, but she nodded and he continued.

"When the process is finished, I could tell you the gender of the baby if you are interested?" He asked.

"Can we decide when the process is done?" Lily asked.

"Of course, it is after all your baby and your choice." He replied with a confident smile.

"Let me go ahead and take the blood samples from you both and set up the retrieval surgery now that way when next we see each other I will be able to give you some good news." He said as he withdrew two syringes.

He quickly drew blood from both and placed in in a cold storage device and they began to discuss payment. Once he gave them the standard fee and they discussed payment methods, the Potters quickly left to go celebrate the good news, leaving their contact information to schedule the return visit.

Later That Evening:

Essex was amazed when he looked at the blood samples that he was comparing to the X-Gene. The only true difference was the placement of a genome in the sequence. In fact, based off his simulations, the two genes would either integrate or fight for dominance. If they fought the gene that succeeded would determine if it were a magical or mutant. He could use a temporary blocker to prevent the merge until he found a way to get the baby back from the Potters. The temporary blocker was a third strand of DNA that he had recovered from Mystique and would help stabilize the genes until he was able to experiment more. He also discovered that no matter the combination, the baby would always be a female.

Essex smiled grimly and began the process to create the embryo. He altered the eggs he had received from Lily potter and introduced Jean Grey's DNA into them and using Mystiques adaptive DNA. With the mix of all three the DNA was stabilized, and the Egg became a mix of Lily Potter and Jean Grey. This would ensure that there was a different DNA strand and if she was a Psychic then she would have a different mental signature than Jean making it harder to find her.

One week Later

Once the Potters returned, he quickly told them that it would only take an hour to place the embryo into her womb. He also informed that there was a complication. Using the story, he had concocted he told them that there were several missing strands In Lily's DNA possibly curse related. He explained that he had another DNA Sample and was able to substitute the missing strands and fix the issue. They were initially upset but eventually the calmed down and stated that they unhappy but accepted that he did everything he could. He led them back into the operating room and had Mr. Potter wait in the observation room. The procedure was flawless and within two hours Mrs. Potter was ready to depart and Mr. Essex was 500 Galleons richer.

"Before we leave," Started Mrs. Potter. "We would like to know the gender of the baby."

"The baby will be a girl." He said with a smile. "If it is not too presumptive would you tell me the name of your daughter?"

"I believe we decided on Dahlia Mira Potter, because she is our miracle." James said with a huge smile, that was only matched by Lily. "And Dahlia because it followers Lily's family of naming the girls after flowers."

"Then I wish you all the best and hope you both live long and prosperous lives, especially with this Dark Lord person."

"I agree and thank you again Nathan." Lily said while she gave him a hug. "You don't know how much this means to both of us."

"It was my pleasure, and I hope to see you again if you decide to have another child." He replied.

"We will." James said, as he shook Nathaniel's hand.

The Potters left, and Nathaniel returned to his lab and continued experimenting with magical blood, but he soon discovered that all his magical blood had disappeared. He quickly went to review the cameras and discovered that the blood disappeared the exact time he said goodbye to the Potters and had finished their contract for the procedure.

"Interesting," He said. "I guess I will just have to wait until I get my hands on the Dahlia in person."

Nine months later, Dahlia Mira Potter was born, and within two months she had her first bout of accidental magic. She caused her bottle of milk to float over to where she was laying in her crib, drank it and levitated it back to the astonishment of her parents. They also discovered that she was a Metamorphamagus, because when Lily would pick her up her hair and eyes would match, and when Sirius did it the same thing happened.

They decided to place a toddler block on her magic to freeze her in a form that was a mix of James and Lily. It also reduced the amount of accidental or in this case purposeful magic, that she could do.

As time went on Lily noticed certain things about Dahlia, like when someone would walk into the room, she would focus on them and follow them. Sometimes when Lily would ask her questions, she would even nod her head or shake her head.

Lily was proud of her daughter, but she was also concerned. It was almost Dahlia's Birthday and she still had not said her first words. She was usually a quiet child, even with other children like Neville Longbottom. She particularly liked it when Tonks was babysitting her with Bill Weasley.

Then on her birthday she tottered into the study where James, Lily and the rest of the marauders were gathered plus the Weasleys and the Tonks. She walked up to her mother with a massive grin and spoke.

"Thank you for the birthday mummy and daddy!"

The entire room froze, and Lily swooped her up and hugged her tightly, with happy tears in her eyes.

"Your welcome baby!" Lily said as James joined the hug. "I'm so proud of you! Those were your first words; you're my little genius aren't you!"

"That's right our little genius! Now I can teach her pranks;" he exclaimed then when Lily glared at him. "I mean manners and etiquette."

Soon the party was in full swing with Dahlia tottering around the room saying everyone's names. She even said Nymphadora correctly, which caused everyone to laugh at the expression of Nymphadora's face!

Once the party was over and everything was picked and cleaned up. The only people left were The Potters, Sirius, and Pettigrew after setting down to a celebratory drink they were interrupted by the sound of the fireplace roaring. When they turned to see who it was, they were met with a grim faced Albus Dumbledore.

"Albus!" James exclaimed "You are a little late my friend, but we saved you some cake."

"I am afraid we don't have time for cake right now." He replied. "I just came from a meeting where I was given a prophecy, it speaks of a child born at the end of July who would be the one to defeat the dark lord. Both Dahlia and Neville fit this prophecy."

"That's horrible!" Lily exclaimed, "But they're both babies how would they be able to defeat a dark lord?"

"I don't know, but that isn't the worst news." He said gravely. "A death eater overheard part of the prophecy and left immediately to inform his master. You need to go into hiding."

"We should be safe here at Potter Manor." James said. "The wards have never been breached."

"I had an idea as well and I think you should use the Fidelius charm on my cottage in Godric's Hollow." He said, while under the table he is both Lily and James with a minor compulsion charm. "Don't you agree?"

For a moment he feared it did not work, but James nodded, and plans were made. Pettigrew would be the secret keeper, while everyone would assume it was Sirius. This way Peter would report the location to Tom and Dahlia would defeat the Dark Lord, and if she did not then He would be able to defeat him after she was defeated.

Albus stared at his reflection in the mirror, trying to figure a way to assuage his guilt towards the actions he had taken. Deep down he knew that he couldn't beat Tom, so it fell to others until he heard the prophecy. With this beacon of hope he could save everyone. He raised his wand, pointing it at his forehead focusing on his memory of his reprehensible action. It was all for the greater good after all. He steeled himself and cast the spell that would assuage his guilt.

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