A/N: According to some sources, Lavender dies during/shortly after the Battle of Hogwarts because of her injuries. However, since it's still (as far as I know) up for debate, she lives in my headcanon. And sorry if you don't think that the ending is a "real ending", but it's where this story ends.
The Battle of Hogwarts was over. Voldemort had been defeated. Most people were sitting in the Great Hall, resting, talking, some mourning. Seamus wasn't resting. He'd looked all over the castle for Lavender, and couldn't find her. He'd looked in the dead – she wasn't there, thank goodness she wasn't there. She wasn't with the sick, she wasn't in the celebration.
And then, walking past the door to the Hospital Wing one more time, he heard voices – "She's been hurt, badly – maybe Greyback." "Found her on one of those collapsed balconies." His heart dropped to his stomach. He had seen Lavender fighting on one of the balconies. He raced into the Hospital Wing…and there she was: unconscious, bloody wounds on her face and arms, blood stains on her clothes…
"What happened?" he asked Madam Pomfrey. "Will she be all right? How long has she been like this? When – "
"Calm down, Mr. Finnigan." Madam Pomfrey said sternly. He stayed quiet, but it took all of his effort not to demand answers. "We think she was attacked by Greyback. As for her future…I haven't had a chance to look properly at her injuries, but it doesn't look good."
He sat in a chair next to Lavender's bed. "I'm going to have to ask you to leave, Mr. Finnigan." Madam Pomfrey said.
"I'm staying," he replied firmly. "And it'll be bloody useless trying to get me to change my mind."
He stayed. When she was transferred to St. Mungo's, he Apparated there and stayed. He stayed by her side, waiting for her to wake up and praying that she would.
