Parvati grieves for her friend Lavender. Her family takes her to away to heal.
This might be a bit contentious as I will be referencing non-Western magical traditions and mysticism due to the Patils having possible South Asian origins as a family.
The River's Song
"Lav! Wait for me!" Parvati's voice echoed through the corridors. "Please wait!" Startled students watched as the eighth-year twins ran through the halls. The leading twin dashed through the hall and out into the castle's forecourt.
"Parv! Stop please!" Her sister gripped her by the arm and struck her across the face.
"Wake up! She is no longer here… Lavender is dead. She has been dead since May..." a tearful Padma pulled her into a crushing hug as Madam Pomfrey and Professor Trelawney caught up.
"I saw her. I really saw her…" Parvati whimpered into her sister's neck. Padma sighed wearily, exchanging glances with the matron. They had already run multiple diagnostic tests for lingering hexes or charms. They were negative. Her twin had not been Confounded, not even during the Battle of Hogwarts. Letters had been sent to their parents, pending their decision on how their daughter should be treated despite the twins already being of age.
Their friend had died during the battle, savaged by the werewolf Greyback. Lavender had still been alive when they brought her to be treated. Parvati had been among those helping Madam Pomfrey treat the wounded during the break in the fighting. Lavender had been too badly mauled. The dreadful wounds to her throat would not stop bleeding. Curse-wounds never healed easy. Padma had found her twin still bent over her friend when she brought another of the fallen into the Great Hall. By then poor Lavender had died.
For a while it seemed everything would be fine. They grieved over a friend lost. The sisters had their share of nightmares over the summer. Their family healer prescribed Dreamless Sleep and meditation. The memories became less sharp for Padma. It had appeared the same for her twin. The Patils discussed if their daughters should continue as private NEWT candidates or return to Hogwarts to repeat their final year. The girls decided to return. Or rather, Parvati insisted on returning. Self-study would have suited Padma just fine.
It was then that Parvati started seeing Lavender. Parvati could smell her perfume and hear her laugh as she stepped into the dorm. Hermione found her weeping as she sat in what had been Lavender's bed after her Advanced Arithmancy. When Parvati looked at Lavender's old seat in Potions, she saw her best friend. She got upset when Professor Slughorn insisted she find herself a partner for his class. She already had Lavender. A fit of hysterics ended with her in the infirmary dosed with a Calming Draught. Yet Parvati was convinced her dead friend was sitting by her bedside as she drowsed.
Hermione was discussing Muggle mind-healing theories with Padma and Luna at the Ravenclaw table when Parvati burst into the Great Hall frantically looking for her friend. She even asked a bewildered Nearly-Headless Nick if Lavender was haunting the school.
"I thought Luna was the loony one!" Pansy Parkinson had thrown the barb before Padma hexed her. They had to restrain Parvati with a Full Body Bind to send her to the infirmary again.
"She's not here as a ghost. We would know, wouldn't we?" Myrtle snapped when the sisters asked her. The ghost folded her arms and gave Parvati an almost pitying look.
"She has let go and moved on. You must let her go. I wish we could move on too…" Myrtle moaned as she sank back into the sink.
Professor Trelawney tried burning sage to cleanse her stricken student's energies and having Parvati wear protective crystals, much to Pomfrey's disdain. When Parvati started sleepwalking, Mrs Norris would walk with her while the caretaker fetched her Head of House to guide her back to bed. Parvati sneaked out of the Gryffindor Tower one rainy night, convinced Lavender was waiting for her on top of the Astronomy Tower. Peeves raised such a commotion that half of Hogwarts were roused from their beds. It took them almost an hour to coax her off the parapet
After the latest scare, Parvati was admitted into St Mungo's.
"You do not have to come with me, Padma… Lav's with me," Parvati murmured sleepily. Padma did not reply but gave her hand a squeeze. She did not appear to notice Lavender Brown sitting at the foot of the cot. An offer to obliviate the patient incited hysteria. Parvati did not want to forget her best friend despite all the painful memories.
She's not healing mentally, Mr Patil. We have done what we could…
The chief healer explained to the parents and shook his head. Hermione discreetly slipped Padma some mental health contacts she obtained from her parents. It seemed that magical mental health treatments were lacking. No one knew if there were any squibs qualified as mental health professionals in the Muggle world.
Luna dropped by to visit the twins at St Mungo's. The family rarely left Parvati unattended. Even while she slept, Mrs Patil or her twin was at her bedside.
"Luna, I am afraid I'm losing her," Padma had confided in her younger housemate.
"Sometimes to move forward, you must move back," Luna had replied dreamily as she toyed with her new bead bracelet. "To heal, one must find balance. Oh, is that a blithering humdinger? They fed off memories, mostly sad ones… You must have so many happy ones to keep them away. Upsets their tummies."
Dreamy Luna was off discussing her invisible creatures. Padma shook her head as she tried to keep up. Some things never change.
Parvati was in no state to continue her studies. Padma put her own studies at Hogwarts on hold for her twin's sake. The headmistress drew up a personal lesson plan for Padma and gave the Patils contacts of qualified private tutors who were also reasonably priced.
"Remember the ashram? Dadi used to take us down to the river to bathe as children…" Padma explained as she guided her sister along. Her parents were speaking with the family elders, desperate to heal their daughter. Parvati appeared trapped in some dream-world no one else could access.
They had gone back to their ancestral seat in the Himalayan foothills. Dadi was still living there, their ancient grandmother with her wispy white hair and walnut-brown face. She kissed both young witches on the brow and gave them her blessings. There were sweets and cakes on the terrace paired with hot tea. Parvati only ate with much coaxing from her mother. She did set aside a plate of sweets and a cup of hot tea for Lavender.
Parvati smiled at her friend. She had never thought Lavender Brown would agree to come with her to so distant and foreign a place. The monkeys that roamed the grounds with impunity should have sent her screaming. The cobra curled up in Dadi's lap as she fed it a bowl of milk would have driven her friend to hysteria. Her clothes had changed too. No longer was she wearing her school robes in Gryffindor colours, but a sari much like that the twins were dressed in for the visit.
The ashram was quietly bustling even at the late hour of their arrival. Dadi's students were busy at their astrology, healing, and other classes. Soft healing chants could be heard from the gazebos. There were stray booms from the old temple ruins where a banishing class was in session. Dadi made polite conversation, trying to engage her ailing granddaughter. She discussed their studies at Hogwarts, tutting at the lack of proper lessons in healing and over-reliance on wandwork. When Mr Patil protested at the lack of progress in Parvati's recovery in the second week, she shushed him with an imperious wave of her bangled hand.
"Patience, my son. For everything there is a season… Your daughter will be healed when the river descends from the heavens."
The twins stayed behind with Dadi when their parents returned to London. Padma took lessons alongside Dadi's students when she was not caring for her sister.
She has a soothing voice, doesn't she? Lavender turned to her smiling. Heavy earrings dangled from her ears. The beads on her red sari glinted. Padma had taken solace in the traditional dance and storytelling taught at the ashram even as she continued her self-study for the NEWTs. The students, some as young as seven, re-enacted the Ramayana on the lawn by lamplight. Padma was given the honour of narrating the classical tale in English for the benefit of a delegation from Ilvermorny.
They were midway through the performance when a mighty rainstorm broke overhead. Fierce wind-gusts sent tents and shawls flying. Thunder roared and lightning flashed. The older students quickly ushered both guests and their juniors indoors. An oil lamp was knocked over and caught the edge of a billowing curtain. A dancer dressed as a monkey cast an aguamenti using his staff to douse the fire before it could spread. The rain came down hard like stinging pebbles.
You must let me go! Lavender shrieked. A sound that brought Parvati back to the Battle of Hogwarts. Instead of a sari, her dead friend was standing before her in her bloodied school robes, head lolling, throat ripped out. Parvati screamed just as her grandmother reached her and placed a comforting hand over her eyes. She blacked out.
First year…
"Parvati Patil, Gryffindor!"
The first time they met, she was bewildered why she had been Sorted different. Padma was already chatting with an older Ravenclaw girl as if she had known her all her life.
"Come on, we'll be bestest best friends!" Lavender patted the bench next to her when she saw how hesitant Parvati was.
Third year…
The class watched as Hermione grabbed her books and stormed off.
"Don't worry, Professor, we believe in Divination…" Lavender chirped, but Trelawney was already launching into a loud explanation about why Hermione could not have the Gift.
Fifth year…
"Seriously? Ron?"
"Come on, Prav, just because it did not work between him and your sister, doesn't mean he is all that bad…" Lavender cooed over the gift she was preparing for her boyfriend.
"I just thought you might choose Neville or Seamus…" Parvati murmured grumpily. She would look the other way when the pair snogged in the common room. Perhaps she had been jealous.
Final year…
"I thought you would have gone back to that school your granny runs in India," Lavender hugged her the moment she stepped into the common room.
"Our parents tried. We cannot leave…" Parvati explained and made a face. "Compulsory education for all purebloods, yada yada. I see they replaced Snape and Burbage…"
"No one can be worse than Snape…" Lavender squeaked as she picked up the timetable. "Wait, did they write Dark Arts?" Her eyes widened in almost comical horror.
"Yep, and lucky us, we have certified Death Eaters as tutors," Seamus remarked dryly.
The storm had blown out by morning. Parvati awoke to a grey dawn outside. She pulled on her shawl and stepped out barefoot. Lavender walked with her, similarly clad. The river had risen halfway up the ashram's stairs. Parvati gingerly climbed down to the bank. The river was a mighty torrent, threatening to overwhelm all in her way.
Parvati picked her way down the steps with care. Lavender went with her. Dadi and Padma had met her on the terrace. The witches followed her in silence until she reached the water. Dadi waved her arm, casting a protective shield over her granddaughter and started chanting.
You must let go…
Nights where they huddled under the covers long after curfew, chatting while their roommates slept. Lazy weekends in Hogsmeade. Poring over tea leaves in Divination. They had been friends for so long, it seemed too hard…
Let go…
With a deep breath, Parvati closed her eyes and plunged into the icy water. A flash of blond curls. An airy laugh. A kind smile… She lifted her head out of the water and climbed back out. She was alone yet she only felt peace. A golden dawn was spilling over the eastern hills. Her skin was tingling from the cold.
"Welcome back, Parv," her twin greeted her with a warm towel at the top of the stairs while Dadi called them to come in for breakfast before it grew cold.
Author's Notes:
Based on the movie, it seemed poor Lavender Brown was dead while the books suggested she might be still alive, just barely when her fellow students drove Greyback off.
Dadi - grandmother in Bengali