Note: I'm changing the timeline around. In canon, Luctretia Black is older than both Orion Black and Tom Riddle. I have decided to make Orion the eldest with Lucretia and Tom the same age.

Fandom: Harry Potter
Main Pairing: Orion Black III/Theia Johnson
Side Pairings: Arcturus Black/Melania Black, Ignatius Prewett/Lucretia Black, one-sided Walburga Black/Orion Black III, one-sided Tom Riddle/Theia Johnson, and mentions of Regulus Black I/Shanti Patil
Warnings: alternate universe; female!Harry (Harriet turned Theia); time travel; het; Walburga Black is a witch and her parents aren't much better; mild language; a large Black family with plenty of Original Characters; Tom Riddle is a creep; bashing of Sirius Black the Second; and mild physical violence

Summary: Harriet Potter wished on to star to save Sirius. She traveled back in time to meet the Blacks of the 1940s, and she became Theia Johnson.

Wish Upon a Star
Chapter I

Harriet Dorothea Potter, commonly known as Harri, was hiding. She was curled up with Buckbeak in the Master Room of Number Twelve Grimmauld Place. Absentmindedly, she stroked his feathers while softly crying. Her godfather, Sirius Black, had died recently. She couldn't believe he was gone. Sirius was the closest thing she had to family. She took a deep breath, and she choked back a sob as she tried to force herself to refrain from crying.

Rolling onto her side, she turned gaze towards the window and peered out at the stars. Sirius shined bright tonight. She caught sight of a shooting star and recalled her Aunt Petunia's words to Dudley when they were children: "If you wish on a shooting star, it'll come true." It was one of the few mentions of magic Dudley got as they were growing up. Harri had plenty mentions of magic, all of which were magic didn't exist.

"I wish I could save Sirius," Harri whispered as she saw the star.

A few more tears streaked down her face as she watched the star until it faded from her view. Suddenly, Harri was overcome with tiredness, and fell into a dreamless sleep.

...

When Harri awoke, she found she was well rested. A moment later, she felt the pressure of something pressed against her throat. She opened her eyes to find herself staring at four wands. The owners of those wands were a middle-aged couple, a teenage wizard, and a teenage witch. Each wore a carefully placed mask of indifference, but Harri could see the curiosity in the eyes of the teenagers.

"Where are you from?" demanded the middle-aged wizard, his grey eyes narrowed at Harri as he carefully watched the teenager. His wand was on her throat.

Harri frowned at the question, clearly confused. Where was she from? That made no sense. She was from England, but specifically she was from Number Twelve Grimmauld Place from London.

The middle-aged witch glared at her husband before turning her kind blue eyes back to Harri. "We know you're not from our time," she said softly. "What year are you from?"

Harri's emerald eyes widened. Had she traveled through time? How was that possible? She knew time travel was impossible without the use of a time-turner. A time-turner could only go back a few hours. "I'm from July 1996," she replied. "Where am I?" she asked, glancing around. She was in the corner of a bedroom.

"The Black London Townhouse – Grimmauld Place," replied the middle-aged witch. "It's July 12 of 1941."

Harri's eyes widened. She was over fifty years in the past. That was impossible! But she was Harri Potter, she was famous for doing the impossible. She was the only (known) survivor of the Killing Curse.

"What's your name?" barked the middle-aged wizard.

Both of the teenagers perked up at the question, their eyes still burning with curiosity.

"Harriet Potter," she replied, wrinkling her nose at the use of her first name. She had never liked her name – she even disliked her nickname of Harri. Harri was given to her by a muggle schoolteacher, and the nickname stuck.

"That's a muggle name," stated the teenaged witch.

Harri was about to open her mouth to reply that she was a half-blood when she remembered she was in the Black house and, according to Sirius, his family valued and believed in blood purity.

"Behave Lucretia," the middle-aged witch scolded the younger witch, who was probably her daughter. "Do you know what your pure-blood name is?" she asked, turning her attention back to Harri.

Harri frowned and shook her head.

"Surely your parents told you," snapped the middle-aged wizard, glaring at her.

"They were murdered when I was a baby," Harri snapped. She hated talking about her parents and their death.

The two witches gasped at her reply and they lowered their wands. The middle-aged witch looked at Harri with something shining in her eyes.

"We'll just have to give you one," the middle-aged witch declared.

"What's your middle name?" asked the teenage wizard, speaking up for the first time. He copied his mother's and sister's actions and lowered his wand. His smoky grey eyes stared into Harri's, reminding the time traveler of her godfather's eyes.

"Dorothea," Harri replied. "I was named after my grandmother, Dorea."

The middle-aged witch smiled at Harri. "I'm Melania Black," she said. "This is Arcturus Black the Third, and our children Lucretia and Orion the Third."

Harri's eyes widened as she gaze landed on Orion. She knew who he was. Orion Black the Third was Sirius' father.

"Where's Walburga?" she asked, catching the four Blacks' attention.

Orion scowled at the mention of his cousin. "With her parents in Wales," he answered, his tone a little hostel. He loathed his cousin, she was always trying to via for his attention. She was convinced they would marry. "Why?"

"She's your wife," Harri replied.

Orion scowled harder while his sister laughed. Mrs. Black smiled and Mr. Black's eyes narrowed.

"No, that would never happen," Mr. Black said. "Walburga's my cousin – my children's second cousin."

"Where did you get an idea like that?" asked Lucretia, laughter laced in her voice. She was behaving very un-Black like – at least, according to Sirius' description of his relatives. Harri didn't actually know how the Blacks behaved as she only had Sirius' word.

"Sirius," Harri answered. She knew Sirius was the eldest son of Orion and Walburga Black.

"Who would that be?" Orion asked, trying not to snap at the mysterious time traveler. He would never take Walburga as his wife, especially now after meeting Harri. He was going to have Harri as his future wife. Before that, she needed a proper pure-blood name. Her middle was Dorothea, which gave him an idea.

"He was my godfather," Harri replied, "and your son."

"'Was'?" repeated Melania. "What happened – or happens – to my grandson?"

"He was killed in June," Harri replied. "It was my fault. He died trying to save me." Tears started streaming down her face.

Mr. Black lowered his wand as he watched the time traveling teenager begin to cry. He knew she was telling the truth. She was an open-book, and she wore her emotions on her sleeve, so to speak. His grandson's death effected her largely.

Mrs. Black gasped at the fate of her future grandson and she pulled Harri into a cry.

"How did he die?" demanded Orion, his eyes narrowed. He didn't like the fate of his son.

"He was murdered by Bellatrix Black Lestrange," Harri replied as she leaned into Mrs. Black's hug. Her hugs felt nice, better than Mrs. Weasley's had ever felt. "She was his cousin."

"My daughter would do that?" Lucretia asked, disbelief in her voice and her eyes widened in fear. A Black never killed a Black. It was the root of the family's very motto. Toujours pur. Always pure. Their family, way back to King Arthur's time, never killed one another.

Harri shook her head. "She's Cygnus and Druella's eldest daughter," she replied. Closing her eyes, Harri pictured the Black Family Tapestry. She opened her eyes and said, "You never had any children. According to the Tapestry, you and Ignatius were murdered in 1961, around the time Regulus was born."

Mr. Black made a note to deny a marriage between Cygnus Black and Druella Rosier. He knew his nephew was close to her, but that union wouldn't happen under the Black family. If they married, they would be Crygnus and Druella Rosier. He would not have Druella's children murdering his future grandchildren.

"D-do you know how I died?" Lucretia asked, her eyes still wide. She was supposed to die in seventeen years at the age of thirty. On the bright side, she didn't have to worry about telling her father she was dating Ignatius Prewett.

Harri narrowed her eyes and she thought. She recalled what she read The Black Family Grimoire. The section on the family history had a family tree, and the cause of death was recorded for each family member.

"It was a Death Eater attack on Diagon Alley," Harri answered. She loved her eidetic memory.

"What's a Death Eater?" asked Mr. Black. Whatever it was, he was going to see there was never such a thing.

"What about this Regulus you mentioned?" Mrs. Black asked, her eyes shining with hope. "Is he another grandson?"

Harri turned to Mrs. Black and nodded. "He was Sirius' younger brother," she answered. Orion paid more attention and leaned in closer. "He died in 1979 while serving Voldemort."

Orion's eyes narrowed. From what he could piece together, his youngest son died at the age of eighteen, and his eldest son was killed by his cousin at the age of thirty-seven. There were a number of things he would do differently so the same fate wouldn't befall his children.

"Who's this Voldemort?" demanded Mr. Black. Regulus was serving this man. Last Mr. Black checked, Blacks didn't serve anyone but themselves – and the Queen.

"The Dark Lord," Harri replied. "He raises the power in the seventies, I think. His followers are the Death Eaters." Taking a moment, Harri burrowed further into Mrs. Black's arms. The feeling of being held made Harri feel safe, something she wasn't use to feeling.

Mr. Black's eyes narrowed. He had a lot of planning to do. He would see to it that this Voldemort, Dark Lord or not, never rose to power and his Death Eaters were nothing more than a dream.

"Voldmort's real name is Tom Riddle," Harri added.

Lucretia's eyes widened at the name while her brother started to foam with rage.

"Tom Riddle is in a Slytherin," Lucretia asked. Riddle was in the running for Prefect this year.

"He's the Heir of Slytherin," Harri stated. No one knew that at this point, maybe not even Tom himself.

"We'll talk about this later," Mrs. Black ordered. "It's been an early morning, and we need to take care of Harriet here."

Harri frowned at the use of her full name. She preferred Harri over Harriet, and she barely tolerated Harri.

This fanfiction story is a part of If Wishes Were Upgrades Collection, which is a series of unrelated oneshots and multi-chaptered fanfiction stories based off of drabbles from If Wishes Were Boggarts.

Original: "Thirty Five: Wish"