When Lily heard the frantic knocking on her door, she abandoned the sofa without even pausing her favourite show. She was across the room in a flash, her heart beating erratically. Something must be wrong, she thought.

Opening the door to be faced with the new guy who'd moved in down the hall was a shock. A few days ago, when she'd first seen him lugging boxes up the stairs, she'd admired – from afar – his artistically rumpled hair and skewed glasses. Now, his skin was paler than she remembered and his brown eyes wide.

"Hello?" she asked, confused.

At the sight of her standing there, he cleared his throat and stood up straighter. Some colour flushed back into his cheeks as he spoke. "Um, hi. I'm James, I – uh – I'm new to the building."

He stuck his hand out in her direction, and she took it whilst trying not to laugh.

"I'm Lily," she said and released his hand, smiling. "Was there any particular reason you knocked on my door like you were being chased by an evil wizard?"

She watched the fall of his shoulders as he visibly relaxed. "No reason for your door in particular, I picked one at random. But" –a shy smile stretched across his face– "this is a little embarrassing…"

Lily raised an eyebrow, intrigued.

James took a deep breath. "Lily…" The way he said her name, stretching out the sound, made her feel like his next words were going to be profound. "Are you afraid of spiders?"

The laugh she'd been holding in since he showed up at her door burst out of her. "What?" she spluttered.

Running a hand through his hair, James glanced back at his apartment. Lily noticed for the first time that his door was wide open, as if he'd fled in attack. James looked embarrassed as he looked back at Lily. She realised two things at once: one, he thought she was laughing at him, not the situation; and two, why he was stood at her door in the first place.

She stepped into the hallway and closed the door behind her. When she was over the threshold of his apartment – which was a lot neater than she would've expected – she turned back to address him. "Where's it at, then?"

James just stared at her for a few seconds, stood just outside of his own apartment as she looked back at him from inside. Then, he shook his head with a small smile on his face and stepped around her. He led her into the small kitchen, almost identical to hers, and faced the wall. There was nothing there.

"Shit," James whispered. "Shitting, fucking bollocks."

She stifled a laugh. "Are you always this eloquent?"

He ran his hand through his hair again and groaned. "Sorry."

Lily took a quick visual survey of the room. The counter was bare except for a kettle and a toaster; unlike Lily's kitchen, there were no utensils or pots left out, or magnets stuck to the fridge, but she assumed that within a few more days her own kitchen would be a paradise compared to his. She fixed her gaze back on James, who was looking at her forlornly. "Give me your shoe."

He glanced down at his shoes – expensive looking trainers that clashed slightly with his worn jeans. Lily wondered if he played any sports. "If you're going to hit me with it and then steal it for dragging you out and swearing in your presence, I'd rather not."

"I need a weapon if I'm going to kill the shitting fucking bollocking thing."

The way James pointed accusingly at the wall, Lily would've thought it tried to murder him. "In case my reaction didn't clue you in, it's gone."

Lily sighed. "Okay, James," she began slowly. "Just step back, take off your shoe and give it to me. And whatever you do, don't look up."

James looked up. He jerked back violently, nearly colliding with Lily as he scrambled to move away from the giant spider perching on the ceiling directly above his head. "Why did you tell me to not look up?" he cried.

"Why did you look up when I'd just told you not to?"

He was breathing heavily as he leaned down to untie his laces. "Because that's what I do," he said as he placed the shoe in her outstretched hand. He made a small noise of revulsion as she walked beneath the spider to get to the counter on the other side of the kitchen.

"Are you scared of wasps?" she asked conversationally as she hoisted herself up on the counter. With her feet on the surface, she had to bend her legs to avoid colliding with the ceiling.

"Why?" he replied, backing against the wall.

She took one swing at the spider and crushed it beneath his shoe. As it made contact, James sighed. "Lily," he said her name in the same way he had before and she found herself hoping he'd say it again. "You are my hero."

"Don't worry about it." She hopped off the counter, registering his expression as the shoe came within a metre of him. "I'm absolutely terrified of wasps, so I'll kill your spiders if you take care of my wasps. Do you have any kitchen roll?"

He pointed at a cupboard to her left, not yet unpinning himself from the wall. "And if I'm afraid of wasps?"

She turned away from him to open the cupboard in question and remove the kitchen roll with one hand. She tossed it behind her and waited to hear him catch it and tear off a sheet before holding her hand behind her. Perhaps she was imagining it, but she thought she could feel the heat of his hand as he passed the sheet to her. "Then the deal's off, and you'll have to burn the place down next time you have a spider."

After discarding the used piece of kitchen roll in the bin, she handed James back his shoe. He hesitated slightly before taking it.

"Good thing I can handle wasps then. It's just spiders that completely strip me of any dignity."

"I wouldn't say you have no dignity left." She watched as he put his shoe back on, carefully avoiding any places that may have been touched by the spider. "Okay, no, you have absolutely no dignity left."

James laughed. "Just wait until a wasp gets into your apartment, and you'll be begging for James 'No Dignity' Potter to save you."

"Ah, but it's autumn so we've still got a good few months until wasp season. Until then, I'm Lily 'Your Hero' Evans."

James held out his hand again. Even though it had only been about fifteen minutes since he first offered to shake her hand, it felt like much longer. "So, my hero, do we have a deal?"

Lily grinned and gripped his hand. "We certainly do. Although I'm going to have to give you my number."

With his hand now free from hers, James ran it through his hair again. Her own hand fought the urge to follow its path.

James smirked. It was a peculiar kind of half-smirk, half-smile that fit his face well and gave Lily the impression that it was his signature expression. "Has the charm of my vulnerability and complete lack of dignity won you over already?"

"I meant I'm going to have to give you my number so you don't have to come running down the hall and embarrass yourself every time you need me to rescue you."