Author Notes: Thank you to aigooism and ultrasonicbopfor betaing!

Warning: OCD

One

It started with the number ten.

The number ten had always sounded special to Teddy, a magical number, one that he could rely on to keep him safe. Sometimes, Teddy would close his eyes and spin around ten times while counting the spins under his breath. One, two, three, four, five, six, seven, eight, nine, ten. If he spun fast enough, then maybe, just maybe, his mummy and daddy would come home, and Grandma Andromeda would stop crying on the inside. Whenever Teddy asked about his parents, she would become quiet and go into her room for half the day. Teddy learned how to amuse himself, first with toys, then with numbers, and then with one particular number.

Ten.

Every time Teddy spun around, he couldn't bear the bubble of anticipation inside of him that said maybe this time would be the time and maybe he would finally get what he had always wanted.

Every time, Teddy was disappointed.

Two

When Teddy started at Hogwarts, he counted the number of steps it took to get to class, the number of steps it took to go to the Great Hall, and the number of steps it took to get to Gryffindor Tower. He worked out routes around Hogwarts that allowed him to always end on a multiple of ten. Teddy tried once to end on two-hundred and sixty-two instead of two-hundred and eighty by skipping over one of the staircases, but he found himself unable to concentrate in class until he had written his name down on the parchment ten times.

Three

It took Victoire Weasley three months to get the secret out of him. She was an annoyingly persistent first year, and Teddy didn't know much about her other than the fact her parents and his parents were friends. She took to following him around after she saw him walking a different way to class. Her constant jabber floated after him as Teddy concentrated on counting.

"Why are you taking the long way around?"

"Why don't you go that way?"

"Why are you going this way?"

The questions bubbled around Teddy until he spun around one day and half-shouted, "Because there are 400 steps this way."

Victoire's bright blue eyes opened wide. "Does it matter how many steps there are?"

Teddy sighed. "Of course it does," he told her, with all the self-importance of a lad who was already half-way through his third year at Hogwarts. "It's safer this way."

Victoire's mouth dropped open. "Does that mean monsters will attack me if I don't count 400 steps?"

Teddy shook his head, feeling self-conscious. "The monsters won't get us if we go in multiples of ten," he told her quietly. "But don't tell anybody else this."

She shook her head emphatically, her curls flying. "I won't! I don't want monsters to get me like they did my uncle Fred."

Teddy had heard of Fred Weasley. He had died in a similar way to Teddy's parents, killed by evil wizards who were defeated long ago. "Monsters got my parents too," he said softly. It wasn't a topic that Teddy liked talking about, but there was something about Victoire's bright innocence that made him want to tell her.

For months afterwards, Victoire followed Teddy around Hogwarts whenever she could, and they counted steps together.

Four

"I think you need some help."

Teddy looked up from where he was measuring his parchment. It was supposed to be two feet, but Teddy figured that 60 centimetres was close enough. It was irrational. He knew it was, but he needed it to end on a multiple of ten. If it didn't, then something bad would happen; Teddy knew that with absolute certainty. "What?"

Victoire looked at him earnestly. "This isn't a game anymore, Teddy," she told him. "I know it was a few years ago when we were pretending to run away from the monsters, but counting can't get us away from them. You must know this."

Teddy turned back to his parchment. "I know."

"Then why are you doing this?" Victoire demanded, waving her hand in front of his work. Her red curls were flying as her eyes flashed. "I've seen you. You still take the same way to class every day."

"So?"

Victoire's voice softened. "You must know this is affecting your schoolwork."

Teddy stared at her. "You're not my mother," he said icily.

"But I'm your friend!" Victoire exclaimed.

Slowly, Teddy turned away. "I'm fine," he said as he smoothed out the parchment, his hand brushing over it ten times. "Just leave me alone." When he next looked up, after he had made sure that his parchment was exactly 60 centimetres long, Victoire was gone.

Five

Teddy didn't mind most classes at Hogwarts. In most classes, he could take a deep breath, slow down, and mentally count until he felt comfortable enough to start something. It stopped the thoughts that plagued him about failure and, most of all, it quieted the thought that it was his fault that his parents were dead and that he would ruin the lives of everybody around him.

The counting ended up affecting some of his potions, especially the ones that didn't need to be stirred in multiples of ten, but most of his classmates were worse at potions than he was, so Teddy didn't stand out.

His worst class was Defence against the Dark Arts. He needed to count to ten every time before he cast a spell, which inevitably meant that by the time he had got to the number two, his wand was skidding halfway across the room. Professor Winters kept on giving him disappointed looks that made Teddy squirm and feel guilty. He could do better. He knew he could, but then he wouldn't be able to count.

Six

Teddy wanted to be an Auror. He had wanted that ever since he learned that his godfather Harry was an Auror. Teddy had always looked up to Harry. After all, Harry was the wizard who had defeated the biggest threat the wizarding world had ever seen. Harry was the one who had hoisted Teddy up on his knee and told him stories about his mum and dad. Harry was the one who had told Teddy that he would always protect him, no matter what.

He stared at his OWLs. He had passed almost everything, but his scores were nowhere good enough for him to become an Auror. His worst subjects were Potions and Defence against the Dark Arts; he had failed both subjects. Teddy squinted. His report said: Theodore Lupin has an able mind and performs excellently in the theoretical aspects of DADA. However, Theodore tends to be slow when it comes to reacting in practical situations.

Teddy counted to ten before standing up. Victoire had been right. He needed help.

Seven

"You're right," Teddy said quietly as he found Victoire. "I do need help."

Victoire looked up at him seriously. "I'm glad you figured it out." She stood up and began walking away.

Teddy looked after her in shock. He thought that she was going to help him, not just walk away after he had come to her. "Where are you going?" he called after her. He could feel his heart hammering in his chest as he mentally counted to ten.

Victoire looked back over her shoulder. "We're going to Madam Pomfrey, silly! You didn't think that I could help you with this problem by myself, did you?"

Teddy blinked rapidly before grinning. "Of course, not," he said, and then ran after her. "Say, do you think we could..."

"... take the long way to the Hospital wing?" Victoire finished for him. "Of course." She waggled her finger at him. "Just this last time."

Eight

"Stupefy!" Victoire shouted.

Teddy felt the spell hit him even before he had started counting, and he hit the ground with a thump. He saw Victoire walk over and wave her wand while rolling her eyes. Teddy felt the spell easing off, and he winced as he stood up.

"You idiot," she said good-naturedly. "You were counting again, weren't you?"

"Trying to," Teddy admitted.

"Pretend I'm a Death Eater," Victoire suggested, a mischievous grin on her face. "You have to defeat me; otherwise, You-Know-Who will win."

Teddy rolled his eyes. "But I know you're not. And he's already been defeated."

"Come on," Victoire said. "You have to try. Remember what Madam Pomfrey said? She said that you need to work through it."

"She also said that I need to work through it slowly," Teddy pointed out. He could feel a flare of irritation deep inside him. He knew that Victoire was only trying to help, but he was doing the best he could. He'd been having regular meetings with a psychiatrist from St Mungo's who had prescribed him a medicinal potion as well as working with him using something called cognitive behavioural therapy. Teddy hated the therapy, but the potion was worse; it made him feel tired and his mouth was always dry. But more than anything else, he wanted to become an Auror. So he had to beat this.

Victoire sighed. "Come on. I don't have all day."

Teddy took a deep breath and braced himself in a defensive stance. He tried to clear his mind and think only of the disarming spell. Nothing else, he told himself silently. Nothing else.

Nine

Victoire held his hand tightly as Teddy took the shortest route towards the Great Hall. He tried not to count the number of steps, but in his head, he knew that it was 309. "You're doing great," she whispered in his ear as he sat down.

Teddy managed a smile. His palms were slippery and he could feel sweat trickling down his forehead as he watched the people eat around him. He could see one person eating cereal, two people eating cereal, three people eating cereal... Teddy shook his head and sat on his fingers to stop himself from drumming them on the table.

"Don't count," Victoire told him. "It'll be okay.

As Teddy sat there, he could almost believe her.

Ten

It started with the number ten and it ended with the number ten.

Teddy had managed to achieve ten NEWTs, among them a NEWT for Potions and one for Defence against the Dark Arts. A part of him looked at the number ten and felt a comfortable peace stealing over him, but another part of him sought Victoire out in the crowd and gave her a thumbs-up. "I'm going to get in!" he shouted as she came running over.

"You're going to be an Auror!" she said with a giant grin over her face. "Congratulations!"

"I couldn't have done this without you," Teddy said quietly and meant it. Just two years ago, he had been failing both Potions and Defence against the Dark Arts. It had taken him a lot to go to his professors and explain his problem, but they had allowed him to redo his OWLs the next year.

Victoire punched him in the arm. "What are friends for?"

Teddy laughed as he grabbed her hand to spin her around and around. As they whirled around for the tenth time, he took a deep breath. "One more for luck," he said cheerfully as Victoire gave him a surprised look. He spun her around again and ignored the churning feeling in his stomach. The world wasn't going to end if he ended at eleven. Everything was going to be fine.

She beamed.

-fin