The Hogwarts Express winds through the scenic countryside, making its way from Hogwarts School of Witchcraft and Wizardry back to London. The June sun beats down on the train, its heat magnified through the windows, roasting the students inside. As always, the train home at the end of the school year is a breeding ground for hyperactivity and practical jokes. Students run riot up and down the corridors, making the most of the last few hours in which they are allowed to use magic before their annual two month embargo.

A red-headed sixth-year girl leans out of her compartment to tell off a group of rowdy third years who insist on playing with a screaming yoyo right outside her door. Her green eyes flashing in annoyance, she slams the door and sinks back into her seat, ignoring the questioning looks of the other students in her compartment as she buries her nose in a book once again. The end of term is always a time for high spirits and high jinks, but Lily Evans has been in a bad mood for two weeks straight, and it shows no signs of lifting.

James Potter. The bane of Lily's life. A year ago, Lily despised him. He was a bully, a toerag. He acted like he was God's gift to Hogwarts, strutting about the school, thinking his talent on the Quidditch pitch gave him the authority to hex anyone that got in his way. Lily was disgusted by him. Until sixth year. James returned from the summer holidays with a new attitude. No longer getting his kicks from cursing unsuspecting Slytherins, James was a different person: cool-tempered, sensible and restrained. Plus, James was now a good few inches taller than the previous year, with a touch of dark stubble across his face, and a brilliant smile Lily had never noticed before that gave her goosebumps. Not to mention how funny he suddenly seemed, how she could chat to him for hours at a time which passed like minutes, how half the girls in their year crowded the Quidditch pitch after each match, hoping to get a cheeky wink from Gryffindor's star chaser. And how Lily hated that she was usually one of those girls.

But, as Lily recently discovered, this new James might not be as genuine as she thought.

Late one afternoon, two weeks ago, Lily was studying in a secluded spot in the Hogwarts grounds, a little niche at the side of the castle which was sheltered by a cluster of trees. She had discovered it two years previously, and could always sit there for hours at a time without interruption.

Without warning, James Potter appeared round the corner.

'All right, Evans,' he greeted her smoothly. 'I've been looking for you.'

Lily jumped and sat up straight.

'How on earth did you find me here?' she asked, astonished.

James shrugged. 'Lucky guess,' he said with a grin, tucking a folded piece of parchment into his robes. He flopped down onto the grass in front of her. 'What are you reading?'

Lily held up Guide to Advanced Transfiguration.

James let out a low whistle. 'Leaving it a bit late, aren't you? Exam's tomorrow morning!'

Lily laughed in spite of herself. 'I suppose you know the whole course off by heart, do you?' she teased. He shrugged and ducked his head modestly.

'Want me to test you?' James offered. Lily nodded, holding out the book. James took it from her and flipped through the pages, adjusting his glasses. For a while they sat together in the fading sunlight, taking it in turns to quiz each other on the finer points of the sixth-year Transfiguration syllabus. James answered every question correctly with casual ease, while Lily groaned in frustration every time she made a mistake.

'All right, what is the correct wand movement for a conjuring spell?' James asked.

Lily flicked her wand in demonstration.

'Oi! Watch where you're pointing that thing, Evans!' cried James in mock concern.

'What's wrong, are you worried I'm going to hex you, James?' Lily asked, feigning a sweet smile.

'I haven't forgotten that Furnunculus hex you got me with last year. I've still got the scars, you know!'

'Well, you shouldn't have been picking on Severus Snape then, should you?' she replied sharply. She was not really angry – James had proven over the past year that he had grown up, and Lily had all but forgotten the bullying behaviour of his past. But she was not about to let James get too comfortable.

'Yeah, well … I don't do that anymore,' James said seriously.

'I know.'

Lily smiled at him, but James looked back at her with a solemn expression, an oddly intense look invading his face, and Lily began to feel a slight fluttering sensation in her stomach.

'Come on, we'll miss dinner,' said James, jumping to his feet and holding out a hand to help Lily up. As they walked back to the castle, James was unusually quiet, and Lily herself felt rather tongue-tied. The shy smile James gave her as they separated into their own groups at the Gryffindor table was somehow different to his usual grin. She was not quite sure why, but Lily had a slight feeling of anticipation, as though something exciting was going to happen. Even that evening as she studied, the bubbling in her stomach seemed to grow, and later as she tried to fall asleep, for the first time in a week her head was not filled with the thought of exams.

The next morning after breakfast, Lily strode along a corridor feeling inexplicably light-hearted, despite the fact that her Transfiguration exam was in less than an hour. An explosion of yells suddenly burst from further along the corridor. Lily quickened her pace, anxious to see what was causing the ruckus. She rounded a corner just in time to see a blur of robes: James was rushing at Severus Snape with his wand out, yelling an incantation. A split second later, Severus was flat on his back, blood streaming from his nose. Severus groped for his wand, but as soon as he raised it, it flew from his hand at Sirius Black's yell of 'Expelliarmus!'

Remus Lupin and Peter Pettigrew were hanging onto James's robes to restrain him. Panting, James looked up and for the first time noticed Lily standing watching them with disgust. As Sirius raised his wand again to hex Severus, James laid a hand on Sirius's arm.

'Don't,' James wheezed, his eyes remaining only on Lily. Sirius glanced from James to Lily, gave a contemptuous snort and stowed his wand back in his robes. Severus scrambled back to his feet, and casting James and his friends a disdainful look, he slunk away, obviously decided that four-on-one was not a fight he wanted to pursue. Severus pushed past Lily, giving her a foul look, and disappeared around the corner.

Lily glared furiously at James.

'Evans— ' James began. His face was full of remorse. Remorse at getting caught, Lily thought lividly. James yanked his robes out of his friends' grasp and started towards her.

'Don't bother, James. I don't want to hear it,' Lily spat. Shaking with rage, she was shocked to feel tears forming in her eyes. She spun on her heel and marched back down the corridor, ignoring James's calls of 'Evans!'

She was sickened by how profound an effect James could have on her. She hated how disappointed she felt that everything she had started to think about him was false, that it was all in her head. James was the same arrogant bully he had always been, and she had been too blinded by her desperation to see the best in him to notice it.

Lily refused to speak to James again that day. It was not difficult to avoid him as she and her classmates studied feverishly for their final exam the next morning. Any time James looked like he might be about to approach her, Lily headed for refuge in her dormitory, or a nearby girls' bathroom, or anywhere that James could not follow her.

That evening Lily curled up in a corner of the Gryffindor common room with Advanced Potion Making, trying to memorise recipes for each of the complicated potions Professor Slughorn had covered in the past year. In the classroom Lily was always good at mixing potions, even fairly successful at tweaking the original instructions to create a more effective method. But exams always made Lily nervous and she was terrified that her mind would go blank, like it had done in her Herbology O.W.L. last year, when she had been lucky to scrape an "Acceptable" grade.

The portrait hole opened and James Potter climbed through the entrance. Lily shrank behind her book, realising she did not have time to make a run for it to her dormitory before James noticed her. James cast his eyes around the common room and thankfully did not appear to see her. He, Sirius, Peter and Remus headed for their usual seats beside the fireplace, which seemed to instantly vacate themselves as the four sixth-years approached. Lily breathed a sigh of relief and carried on reading about Amortentia, throwing the occasional innocent glance at the boys beside the fire.As Remus and Peter unpacked their school bags and Sirius assumed his typical bored expression, James furtively glanced around the common room as he fumbled with his bag. Naturally, his eyes eventually fell on Lily. She quickly averted her eyes as though she thought it might stop him recognising her. James whispered something to his friends before vaulting the arm of his chair and making a beeline for Lily.

Lily sighed heavily. She really did not have time for this.

'All right, Evans?' said James smoothly in his usual fashion. The low voice grated on Lily's nerves; she could not imagine how she had ever found it attractive.

'Hello, James.' She tried to sound sophisticated and cold, but her tone seemed to come out slightly high and squeaky.

'Want some help studying? I could quiz you again,' James offered eagerly.

'No thanks, I'm managing fine myself,' she replied coolly.

James regarded her with an amused look for a minute.

'I know why you're angry,' he told her.

'I see,' replied Lily, refusing to rise to the bait. She could not be bothered with another of James's pathetic excuses.

'I apologised to Snape, you know,' he told her earnestly.

'Good for you.' Not believing a word of it, Lily flashed him a quick, tight smile and lifted her textbook up as a barrier between them.

'So … are you still angry at me?'

'Nope,' she replied lightly without looking at him.

'Good. That's great. Because I'm really not the idiot you used to think I was, Evans.'

Lily raised her eyebrows but said nothing, staring fiercely at her textbook.

'Come on, Evans, what more do you want me to say?' James pleaded.

'I'm rather busy here, James. We've got our Potions exam tomorrow in case you've forgotten?'

'Oh relax, it's not like it's our N.E.W.T,' drawled James impatiently.

'I know, but if we don't pass these exams we might not be allowed to carry on with the subject next year,' Lily responded, her voice sounding slightly too shrill. Exam time always made her more tense than she cared to admit.

James rolled his eyes but before he could open his mouth and make another infuriating comment that would tempt Lily to hex him again, she threw him a disdainful look.

'Just because you get "Outstandings" in your sleep doesn't mean the rest of us don't need to study,' she said scathingly.

James laughed. Lily retreated further behind the textbook.

'Evans … look, I'm really sorry. I only hexed Snape because – '

'I don't care why you did it, James!' Lily interrupted. She was furious, but for once she just could not face reiterating all that James had done wrong, and she swallowed her anger and returned to the book, hoping James would take the hint and leave her alone.

After a minute of sitting in silence, just when Lily hoped he was going to give up and leave, James leaned towards her, a serious expression painted on his face.

'You know, I was thinking … maybe during the holidays you might like to meet me for a coffee in Diagon Alley.'

'Get lost, James. This is getting really old,' spat Lily.

She was so sick of the cycle. She would start to believe that James was finally growing up and becoming a decent guy, and then he would prove once again that he was just a conceited, immature bully. Then James would jokingly ask her out, and even though Lily knew he wasn't serious, that he would never really be interested in her, she would think it was sweet, roll her eyes and forgive him, and they would go back to being friends. Well, not this time.

James sighed. 'Okay, Lily.' He was nodding slowly and not smiling. It was the only time Lily could ever remember James calling her by her first name. 'I get it. You win, I'll stop bothering you. I won't ask you out again.'

James got up from the armchair and didn't look back at her as he walked away.

What happened to the sarcastic comment? 'Ah, you'll change your mind soon enough, I've seen how you look at me, Evans,' or 'Come on, Evans, you're breaking my heart.' Lily was thrown by this change in tactic.

Lily watched over the top of her book as James sidled over to his friends. She waited for him to regale the story to them, for the whooping laughter from Sirius, for Remus to smile and say 'Better luck next time,' for Peter to giggle and clap James on the back, and for the four of them openly talked about her.

Nothing. James slumped into a chair and pulled out his Potions textbook. His friends exchanged glances with each other, and Lily saw Remus shake his head warningly at the others. None of them said a word to James.

This was new.

Realisation dawned. James was sulking. How immature. Lily shook her head in disdain and returned to her textbook. The effects of Amortentia can become more acute as the potion ages, although this can be avoided by…

But Lily had never known James to sulk before. Before long she found herself peering over the top of her book again. James was still reading in silence, while his friends chatted quietly around him.

That night, Lily found it difficult to get to sleep. As she tried to mentally run through each of the potions she had memorised, her thoughts were infiltrated by James Potter and his pathetic effort to charm her into forgiving him, his arrogant assumption that she would just forget what he had done … his feeble attempt to gain her sympathy by moping pitifully over his textbook …

Eventually, at a quarter to one, Lily gave up trying to sleep and decided to head back to the common room for a couple of peaceful hours of study. She tugged her dressing gown around her and, afraid of wakening the other girls in her dormitory, she stumbled through the darkness to the door. As she made her way down the stairs to the common room, she heard a couple of soft voices from below, and paused on the stairs as she tried to work out who was still in the common room at this late hour.

'Yeah, I was dying to hex the slimy git, but James told me just to leave it. He's turned into such a goody-two-shoes this term. At this rate he'll end up Head Boy next year.'

It was Sirius Black; he was still lolling in an armchair by the fire, while Remus Lupin sat opposite, a textbook open in his lap, although he was not paying it much attention.

'And then, of course, Snape had to go and mention Lily Evans,' Sirius continued, smirking. 'Snivellus knows exactly how to push James's buttons. The only reason James would bother to fight Snape these days is if he was slagging off Lily.'

'But to James's credit, he actually managed to stop himself before things went too far,' Remus commented. 'It's just a shame Lily had to appear when she did.'

Sirius sniggered. 'Did you see look on her face?'

Remus shook his head. 'Don't. It's such a shame. James has worked really hard to prove to Lily that he's changed, and it's all been for nothing, now.'

'And the fact that he actually apologised to Snivellus afterwards!' exclaimed Sirius, shaking his head in disbelief. 'I thought I might puke!'

Lily straightened up, confused. All thought of the Potions exam had been pushed from her mind. Like a zombie, she made her way back to bed, only one thought circling in her head: James Potter.

On the Hogwarts Express, Lily checks her watch and makes a face. The prefects from each house take turns patrolling the corridors and it is now Gryffindor's turn. Sighing, she rises from her seat and makes her way to join the other five Gryffindor prefects. As she and Remus Lupin patrol the train – normally a mere formality, not requiring much in the way of disciplining the students – Lily takes out her bad mood on any unfortunate soul who crosses her path. Usually she is fairly lenient with the younger students, often laughing at their mischief and their cheek and only enforcing the rules when strictly necessary. Today she stalks up and down the corridors, barking instructions at everybody and even telling off a stunned Remus for not backing her up. At one point Lily finds herself shouting at a tiny first year girl purely because her enormous cat is blocking the corridor, only for the girl to burst into tears and retreat into a compartment, dragging the obese cat after her.

Once the Ravenclaws take over patrolling the corridors, Remus walks Lily back to her compartment in silence.

'Lily …' Remus begins, flinching at her contemptuous expression. 'Look, Lily, I know you are angry with James, but I think you need to talk to him.'

'I don't have anything to say to him,' Lily sniffs.

'Fair enough. But at least listen to what he has to say to you,' Remus counters. 'You don't want to leave things like this over the whole summer.'

As if on cue, a door opens to Lily's right and James's head pops out.

'All right, Evans?'

Lily gives James a small smile and as Remus slips into the compartment, James slides out of it, closing the door behind him.

'Haven't seen much of you lately,' says James softly. He casually leans against the train wall with an eager smile on his face.

'I know. Sorry, I've been busy.' Her words come out rather clipped and impatient. She stands stiffly, feeling incredibly awkward, her arms crossed in front of her.

A battle rages inside Lily. She is furious with James for contradicting everything she started to believe about him; or maybe just furious with herself for falling for his act. But a small voice keeps reminding her that what happened a week ago was an isolated incident, and she knows the real reason behind it. It is still no excuse for attacking someone, but sweet that he was doing it to defend her honour. Apparently James has genuinely changed for the better. But Lily was always stubborn, and she still feels as though James betrayed her somehow, ruining everything for one cheap shot at Severus.

'Any plans this summer?' James asks.

'Oh, the usual. Sunbathing, reading, annoying my sister,' Lily replies, catching herself beginning to smile and quickly painting the indifferent expression back on her face. James laughs uncertainly, his posture becoming awkward to match hers.

'Yeah, me too … nothing special planned …' he trails off. They regard each other in silence for a long while, until Lily feels so uncomfortable she breaks eye contact and stares at their feet.

'Well ... it's been nice talking you, Evans,' says James with a wink. Lily suspects he is making fun of her, and once again feels a quick surge of anger towards him.

'See you next term, James,' she says coolly.

'I'll miss you,' James says softly and lifts a hand towards her face as though he is going to stroke her cheek. Then apprehension clouds his face and he lowers his arm, seeming to change his mind. Lily finds she has been holding her breath, and lets out a tiny sigh. James looks at her intently, as though waiting for something. Lily wants to say something, but the words catch in her throat.

'Well … have a good summer, Evans.' Looking dejected, James reluctantly turns away and disappears into his compartment. Lily finds her feet automatically carrying her back to hers, even though her insides scream at her to go back and say goodbye properly.

As the journey nears its end, the train rocks soothingly and Lily is hypnotised by the rhythm. She has long since given up reading and is now staring idly out of the window. The Hogwarts Express seems to travel a touch faster than the trains she remembers from her muggle childhood, and the fields and forests whip by in a blur.

As always, James finds a way of creeping into Lily's thoughts. Although she tries to push the thought from her mind, she can't help wishing she had found the words to tell James she is not angry anymore. Remus is right: going home for the summer without resolving the tension between them is not a good idea. If she is honest with herself, Lily knows she will miss James as well, and the idea of not seeing him again until September makes her ache with regret.

The Hogwarts Express wheezes to a standstill. Lily heaves her trunk towards the door and hugs her friends goodbye. The doors slide open and Lily jumps down onto the platform, dragging her trunk behind her with a bump. As she heads for the barrier, her eyes automatically search the heaving platform for the familiar head of brown hair. Lily shakes her head, dragging her gaze back to the way ahead, lugging her trunk behind her towards where her parents will be waiting.

Once again Lily finds her gaze pulled backwards towards the crowd. She feels a tugging sensation in her stomach as she searches the students for James. I just need to see him, just for a second, she tells herself. I haven't said goodbye properly.

There he is. Lily can see the side of James's head in the distance as he chats to a group of Gryffindors – the cool ones from the Quidditch team that always seem to stare through Lily as though she is invisible. Lily feels an uncontrollable urge to speak to James, she doesn't think she can bear not seeing him again for two months. Abandoning her trunk, Lily breaks into a jog. Everyone on the platform seems determined to get in her way. She shoves her way past a couple of tangled groups. James is turning away from his team-mates, reaching for his trunk, beginning to move away.

'James!' Lily calls, running along platform. James's messy hair disappears once more in the throng. Lily pushes through a huddle of students, ignoring their objections, and once again manages to catch sight of James as he winds his way through the crowd.

'James!' Lily yells again.

James looks over his shoulder and stops, surprise flooding his face as he notices Lily flying towards him, her red hair whipping at her face.

'Evans! What's up?' says James, looking pleased. His expression turns slightly wary as Lily catches up with him.

She stands in front of him, breathless, knowing her hair is tangled and messy and her cheeks are probably bright red, but it doesn't seem to matter.

'I just wanted to say … goodbye,' Lily breathes.

A slight trace of his old, arrogant expression crosses James's face for a split second, before he breaks into a genuine smile.

'Goodbye Ev— I mean, goodbye Lily.'

For a moment they stand looking at each other in awkward silence, both wearing silly grins. Then as James turns to walk away, Lily catches hold of his hand and leans over to kiss him on the cheek. James's head turns slightly, and Lily's lips land on the side of his mouth. For a second their lips press together, and Lily feels like a wave of electricity is flooding through both of them, from their lips right to the tips of her toes. Around them Lily can hear the students whooping and whistling, but it is all a distant rumble.

She pulls away from James, her heart thudding. He gives her a brilliant smile that does nothing to slow her pulse, then turns and walks away. Lily watches James disappear into the crowd before she turns away too, feeling like she is floating several feet in the air. A grin spreads across her face. Saying goodbye is not always such a bad thing.