A/N: Inspired by the small bit in the HBP movie where Slughorn tells Harry about the gift Lily gave him... "A spring afternoon I discovered a bowl on my desk, just a few inches of clear water in it. Floating on the surface was a flower petal...as I watched, it sank...just before it reached the bottom, it was transformed, into a fish. It was beautiful magic, wondrous to behold. The flower petal had come from a lily, your mother."

Horace Slughorn sat at his desk. Moonlight streamed in through the single window of his office, reflecting off of potions bottles and cauldrons.

The faces of past students smiled at him from the shelf in the corner of the room, but none so brightly as the red-haired witch in the front row. The grin of a young Lily Evans radiated amongst the paled photographs and worn frames. Horace had his back to her, focusing his attention on the tip of his wand rather than the likenesses of his alumni.

The bowl in front of him was filled halfway with water. It was the only thing he'd bothered fixing of his old possessions after the destruction of his office during the Battle of Hogwarts. He'd repaired it to be like new, minus a small chip in the top. It was the only piece that hadn't zoomed back into place when he'd uttered the mending charm.

Flowers floated in the two inches of water. A carnation, a lilac, and even a rose danced a silent waltz on the surface. Several more flowers were formed from a burst of light every time Horace flicked his wand. A daisy, a sunflower, a hydrangea. Several birds of paradise flowers fluttered in the air and came to rest beside the bowl. Tulips, gardenias, poinsettias, orchids… but no lilies.

Horace had given up on creating lilies ages before. He never did them justice; could never match the beauty and delicacy of the one he'd found in the bowl all those years ago.

Horace Slughorn was an old man, but he would never forget the present he'd received from Lily Potter; would never forget Lily Potter herself.

She'd been an extraordinary student. Lily earned top marks in his class and was certainly the brightest witch of her age he had ever met.

He closed his eyes and a vision of a small fish swimming in a perfect bowl of clear water played against his lids. Francis, he'd named it. That fish had been extremely dear to him. Horace opened his eyes to find his vision clouded. He'd never gotten to tell Lily just how much her gift had meant. His letter had gotten lost in transit.

It had truly been such beautiful magic, more precious than anything he'd yet to witness in his life.

Professor Slughorn stopped the mechanical flicking of his wand to put his head in his hands. Even so many years later, he could not find it in himself to get over the injustice, the downright cruelty of what had been done to Lily and her husband. Every time he entered his office after a long day of teaching, Lily's face greeted him from the front row of his shelf. Her smiling face, young and untouched as he'd known it all those years before.

And her eyes. Her deep green eyes, exactly like her son's. Large and round, filled with so much hope and promise. She'd died so young, long before she should have. Lily hadn't gotten to see her son grow up, or the Wizarding World in its absolute prime.

It was all so wretchedly unfair. Voldemort was gone, never to touch another soul again. But that did not repair all the hurt he'd caused, all the lives he'd taken. His defeat did not bring back Remus Lupin and his wife, the young Weasley boy, Albus Dumbledore, or James Potter. His defeat did not bring back Lily.

Professor Slughorn's tears mixed with the water in the bowl beneath him. His old, wrinkled fingers closed around his wand once more.

"Expecto Patronum."

The words left his lips in a whisper, and soon his dark office was illuminated with the billowing magic that was the Patronus charm.

A white fish glided through the air surrounding him, not needing water to swim in. It moved freely about the room, maneuvering through the bars of the window and shaping itself to the outside of the glass bowl. It twisted its pale body among the flowers and stuck its shimmering nose into the water to blow a small amount of bubbles.

A faint fluttering of wings broke Horace from his concentration, and the Patronus vanished in an instant. He turned around to find a small, brown owl resting between the bars of the window. It carried a letter in its beak.

Professor Slughorn stood from his seat and offered his hand to the small bird. It positioned its tiny talons onto his finger and released the letter into his hand. Horace left the small creature on his owl post to shake the snow off his feathers and opened the letter.

Professor,

Wishing you every happiness this holiday season. We do hope you're taking good care of Hogwarts for us.

Warmest regards,

The best students you ever had

The letter was written in what he recognized as Ginny Weasley's neat scroll. Her and Harry Potter's wedding invitation had come to him the previous year, but he'd missed the event with great regret due to illness. After close inspection, he decided the signature was done in none other than Ronald Weasley's messy scrawl. He chuckled to himself. Best students? 'Most reckless' seemed to be a proper title. Or perhaps 'bravest' fit the lot of them just fine.

Behind the letter, a photograph was enclosed. He put on his spectacles to better admire the four familiar faces. Harry, Ginny, Ron, and Hermione smiled up at him.

Horace Slughorn smiled and turned the photo over in his hand. On the back was a messy inscription.

Thought you might like an update. Ginny's expecting (we think it's a boy). Ron finally found it in him to propose to Hermione. Expect their wedding invitation in the following months.

Merry Christmas, Professor. Hope you're well.

Harry

Professor Slughorn grinned again and tucked the letter into the top drawer of his desk. The photo remained in his hand.

Shakily, he made his way to his bookcase and took a frame from the bottom shelf. Leaves made of goblin gold swirled around the dark wood. He placed the photo of Harry and his friends in it, and started on clearing a spot on his famed shelf for it.

"Right there should do," he muttered to himself before standing back to admire the new addition.

The people in the photos looked around to adjust themselves to their new spots. Lily's smile still gleamed in the front row, but it was not directed at him. Her grin faced the photograph beside her, where her son sat with his wife and two dearest friends. The Harry in the picture grinned back at her, then turned his head and waved at Professor Slughorn.

Lily Potter had not died in vain. Because of her, Harry was alive and happy, with a little one on the way. The Wizarding World was safe from harm because she had dared to love her son so much that she would put his life before hers.

Horace Slughorn muttered a quiet incantation under his breath. A single lily emerged from the tip of his wand, a lily as beautiful and delicate as the one he'd found floating in a glass bowl all those years ago.