After some random guessing, she admitted to being a hedgehog... "Did someone do this to you?" He asked slowly. She shook her head. The rustling of her quills was disconcerting, but he was getting use to it. "Did you do this to yourself?" He asked, as the next logical question. She nodded and gave him a proud smile. The odd girl had intentionally mixed her blood with a hedgehog... "I don't know if I can, but would you like me to fix you?" Severus asked. The damage might be irreparable, but he could offer.
The girl shook her head adamantly and a couple of the poison tipped quills fell off of her onto the seat cushion. Severus tried to think of something more to say, but the girl was staring at the pictures in the book again, so he returned to his own reading. Eventually the train reached his stop and he stood to exit. The girl followed him. He wandered around the town until he found an inn, and the girl shuffled after him. She tripped a number of times over his robe, but he did not help her up.
When he had reached a suitable inn he paid for a room and wandered up to it to rest. Still the girl shadowed him. "Don't you have anywhere else to be?" He snapped as he opened the door to his room. She shook her head and dropped more quills in the hall. Severus groaned. Now that he had a chance to think about it, he was familiar with the type of poison she was covered in. There was a good chance that the poisonous properties had worn off an hour ago due to exposure to the air... but it would still make anyone violently ill if they got pricked by her.
He ushered her inside and pointed her to the bathroom. "When you come out, I expect every speck of black to be gone." He didn't actually expect that, but he wanted her clean. The poison was water soluble, and wouldn't be terrible to get off, but he was NOT going to be helping her scrub her back. When she had locked the door he changed out of his traveling cloths and into something more comfortable. A simple black robe would do.
He took a coin from the purse Minerva had given him, and went out to see if a local bookstore was still open. He was in luck. It was. He asked the store owner for the books he was interested in, paid with a coin, and flipped one of the books to the page he was interested it. "The proper care and feeding of your new hedgehog." Perfect. It wasn't impossible for a human animal transformation to go wrong, but the hybrid that was born of it would need to remember its peculiar dietary needs.
When he had the information he needed he went to a close by general store and picked up the food items he would be needing. A pink hooded parka caught his eye while he was waiting to purchase his food items, so he picked it up as well. His old robe would need to be thrown out. When he had all of his things, he returned to his room at the inn, knocking before he entered. He heard an odd scraping sound that he assumed was the girl pawing the ground as permission for him to enter.
He cracked the door open to be sure. She was wrapped in a towel, but there wasn't much else for her to be dressed in. Severus dropped his purchases on the bed and went to the bathroom to do damage control. He expected to find smudgy black paw prints on every surface available, and small pools of black goop and quills on the floor. What he found instead blew his mind. "Did you do this?" He snapped. She nodded. "How in the fairying forests did you manage to do THIS." He stared at her abashed. She did no more than look at the ground.