It was the coldest day of December, and Lily's apartment felt like an icebox. She lay on her bed – or, more accurately, on a mattress on the floor; she had been meaning to buy a bed since she had moved in, but never found the time to do it – under a thick pile of covers, but she was still shivering so hard that she could hardly concentrate on the book she was reading (Morella Amaranta's Life Without Death – an extensive history of wizardkind's pursuit of immortality).

As if her senses hadn't been dull enough already, she also felt like she had been slapped in the face with a frying pan. She hadn't slept all week, and her body was screaming all over. All of her muscles were sore and her head was throbbing like someone was squeezing her skull. Much like Severus before her, she found herself unable to sleep because her many duties kept her busy from the crack of dawn past midnight. Her worries and fears often kept her up during the rest of the hours of the day. .

A lot had changed since August, when Lily had still been unemployed and alone and grieving for her lost child. She had moved out of Petunia's house and gotten a place of her own; a rat-infested studio in London she could only scarcely afford. She had gotten a job as a subeditor for Witch Weekly magazine. She had cut her hair, lost a lot of weight, and picked up the habit of practicing counter-curses, Occlumency, and other useful skills every morning.

She had contacted the Order of the Phoenix and revealed herself as Cassandra Queen, the extraordinary Seer.

She was still grieving for Harry.

She had felt dizzy since the meeting with Dumbledore and the rest of the Order, as if she had just climbed on a mountain and looked down for the first time. She had been pulling strings left and right ever since Sirius had died, but it was only now starting to feel real – that she was really doing this, disturbing the universe like she owned it.

Ever since February, Lily had only had four things on her mind. Firstly, she had needed to get Harry somewhere safe. This had been her top priority, which had kept her away from the wizarding world for the next eight months – but which had not prevented her from plotting and planning how to deal with the rest of her to-do list.

Secondly, she had sworn to save each and every victim of a Death Eater attack and assassination she knew of. She had written dozens and dozens of letters to potential victims of Voldemort, and sometimes to Daily Prophet just to let everyone know of her existence. She had feared that people would not believe Cassandra Queen's warnings if they had no proof of her competence.

Here, Severus's journal had proved immensely useful. She had used every memory-enhancing spell in her repertoire to be able to remember every last page of the book, which contained detailed accounts of Voldemort's operations during the war. She now knew everything Severus had known of at the time, and used her knowledge to warn people of impending attacks. Many of Voldemort's plots had been trumped at the last minute thanks to Cassandra Queen's prophecies.

Still, Lily had not been able to rescue everyone. Professor Flitwick, who had been alive and well in the future, had been murdered by Death Eaters in Hogsmeade. Lily had successfully managed to prevent the first assassination attempt of Westley Thomas – a pure-blood wizard who had refused to join Voldemort – but a month later the poor man had been killed anyway. A book shop owned by a Muggle-born witch had been burned down, even though there was no mention of such event in Severus's journal. It was clear that the more she altered the present, the less accurate her predictions became as history reshaped itself and drifted further into the unknown. One day, it would be as if she'd never even seen the future.

But she would not be weak. Never again.

She had thought about her battle plan for a very long time, and in the end she had concluded that she needed to work with the Order if she really wanted to make a difference. Writing cautionary letters to individuals was one thing she could manage on her own, but for everything else she was going to need allies. She needed to find out how to defeat both Voldemort and his band of devoted followers, and she simply couldn't do it single-handedly. She needed the help of stronger hands and minds.

But she was not going to be their silent servant. She was not going to give up her secrets only to see Dumbledore use them for his own twisted ends. She was going to work with the Order, but not for them.

Fortunately, Dumbledore had agreed to her conditions. He had written her after the meeting to inform her that the Order was grateful for any help she was willing to provide, and that her views would always be respected. She wasn't sure if she trusted him, but it was a start.

Thirdly, Lily planned to find a way to vanquish Voldemort for all eternity.

She was still working on it.

She still didn't know how Voldemort had been defeated in the future. She knew that Dumbledore had been working with Harry to undo the spells that had made the Dark Lord immortal, but she wasn't familiar the specifics of their plan. All she knew was what Severus had told him, and it wasn't much. Dumbledore had kept him in the dark most of the time, fearing that Voldemort might discover his scheme through Severus. Severus had told her that the plan had something to do with certain relics – a cursed ring and Godric Gryffindor's sword, for instance – but he hadn't known what the objects had in common, or how they all tied to Voldemort's immortality.

Before returning to the past, Lily had read all about the fall of Voldemort in the papers, but none of them revealed the details of his death. She never learned how Voldemort had turned himself immortal or why he had become mortal again. She could see why; one would not exactly leak the secret of eternal life to the press like it was celebrity gossip. Perhaps the only people who knew the truth were Harry and his closest allies.

But if they had discovered it, so could she. Knowing that Harry eventually had broken Voldemort's defenses gave her faith, and so she spent most of her nights researching to figure out how Voldemort had made himself invincible. Discovering the key to immortality wouldn't be easy, but it was possible. And in any case, it couldn't be any harder than learning how to travel through time.

Lastly, she intended to find Severus.

She gazed at Psyche – her new owl – and wondered whether she should try to write him yet another letter. Would it reach him this time, or would Psyche return to her with an unopened envelope?

Lily had already sent Severus dozens of messages, and she was yet to receive an answer to any of them. At first, she'd thought that he was simply too angry with her to reply, but then she had discovered that Severus had disappeared. James had attacked him in Hogsmeade a couple of weeks after Sirius's death, and he had since left Hogwarts. Nobody seemed to know where he had gone to after that. Nobody cared.

She imagined that he might have made himself unplottable because of James. Maybe he feared that James was going to track him down and attempt to murder him again. It was also possible that he couldn't reply to her letters because he was already dead, but she tried not to think about that.

She had eventually decided to pay a visit to Severus's father, who still lived in Spinner's End. She had been hoping to find out where Severus was, but Tobias Snape hadn't seen his son in years.

Lily and Mr. Snape – who looked very much like his son, save for the bushy moustache – had exchanged a few words by the front door. She hadn't learned anything new from him. He had told her that Severus had stormed off after a fight years ago, and that he had never returned.

She had left him her phone number – she'd gotten herself a phone because of Petunia – and asked him to contact her if Severus happened to show up.

"If you do find him," Mr. Snape had told her before she had left, "Tell him to drop by for a cuppa."

Since that day, she had had as little luck in trying to find him. She had tried to locate him using a number of tracking spells, with no results. She had visited potion breweries, herbariums, apothecaries – places she imagined he might have turned to for work – but to no avail. She had contacted the staff at Hogwarts under various excuses to inquire about their former Potions Master, but none of them could tell where he was now. Wherever Severus was, he was clearly maintaining a very low profile.

If he was even alive.

Every day, the idea that something terrible had happened to Severus seemed more and more likely. She had to consider the miserable possibility that he was lying in an unmarked grave, brutally murdered by any of the people who wanted him death. Perhaps he had fallen in the battlefield, and that his death had simply gone unannounced. Maybe James had found him, and finished what he had started in the Three Broomsticks. He could have been killed by a fellow Death Eater or Voldemort himself for any reason. Or perhaps he had been captured, and was currently being held and tortured for information in some secret Auror base.

She was still trying to find him, but the truth was she didn't even know where to look for him. The only sure way to contact him was to appear at the site of a Death Eater attack and call his name, but not even she was brash and stupid enough to call that a decent plan. Having both of them killed in the crossfire was not her idea of a romantic reunion.

Once again, Lily thought about the last time she had seen Severus. She tried to remember what his hands had felt like when they had moved up and down her bare skin, but the memory of that night was fading away. Still, it was enough to derail her thoughts. She put down her book, knowing that she was not going to get any more reading done that day.

It was only afternoon, but she was already exhausted. Being a part-time Order of the Phoenix consultant while trying to discover a way to defeat Voldemort and while also obsessively looking for Severus was really taking its toll on her now that she was also trying hold down a day job. She had a feeling she wasn't going to last at Witch Weekly very long if she continued to turn up at the office so tired she could barely stand straight, let alone work. She needed sleep, preferably through the whole weekend.

She went to her kitchen cabinet and grabbed a vial of mild sleeping draught. It was empty. She briefly considered trying to fall asleep without the aid of a potion, but feared that she would just end up staring at the ceiling for hours. It felt wiser to grab a coat and head to Diagon Alley for a quick supply run.

Twenty minutes later, she found herself in Slug and Jiggers Apothecary staring at a selection of sleeping potions, all neatly lined up in a display case. She sneered at the ridiculously pricy ready-made brews and was just about to turn away and pick up the ingredients to make one of her own when something grabbed her attention.

Her body reacted instantly, like she had been struck by a lightning, and it wasn't until a heartbeat later when her mind caught up with what she was looking at. There, right at the level of her eyes, sat a small vial of Dreamshade potion. There wasn't anything peculiar about the potion itself. It was the hand-written label that made her hitch her breath and grab the vial with a trembling hand.

He had written her dozens, maybe hundreds of letters in her lifetime. She knew his handwriting as well as she knew the sound of his voice. When she traced the letters with her finger, she could almost picture his hand inking them down.

This potion had been brewed and bottled by Severus Snape. She was absolutely sure of it. Now all she had to do was to find out where it had come from, and she would find her way back to him.

A few strategic lies, a couple of veiled threats, and a covert sexual suggestion later, she had persuaded the cashier to tell her how to get in touch with the independent supplier who had provided the potion. The man behind the counter had written the supplier's name down on a piece of paper, which Lily had accepted as calmly as she could before scurrying outside in the street. There, she opened the folded paper and nearly shrieked out of joy when she read what was written on it.

Mr. Sebastian Spectre, Potions Master.

No address, but it did not matter. All she needed was a name to get her letter through to him. And if "Sebastian Spectre" wasn't the nom de guerre of certain someone, she was going to eat her boots.

That night, she composed a letter to Mr. Spectre. She chose her words very carefully, just in case the letter ended up in the wrong hands, and she hoped that the short cryptic message would be enough to spark Severus's interest.

Dear Mr. S,

We need to talk about the Half-Blood Prince.

Sincerely,

L

She gave the letter to Psyche and kissed the little owl for good luck, praying that this time her search would bear results.

A few days went by. She kept waiting for the response that never came, wondering whether she had made a mistake in assuming that Severus Snape and Sebastian Spectre were the same person.

By Thursday, she was a wreck. Severus still hadn't replied to her, and the whole ordeal was starting to seem like another dead end. Still, she kept glancing at the office window at work, hoping to see an owl with a letter in its beak perched on the window sill every time she looked outside.

She never did.

"Not bad. Quite nice, actually," said Martina Mayfield – a gossipy fashion editor who shared an office with Lily. They were having a break, and Lily was slouching on her chair trying to will herself to eat something; she hadn't had an appetite all week. Martina was drinking her tea by the window and staring at the busy street behind the glass.

"What is?" asked Lily.

"That man you've been eyeing all day," Martina replied, "An odd-looking fellow, but in a good way. Tall, and dark, and mysterious..."

Lily raised her head. "What man?"

Martina smirked at her.

"Oh, come on. I'm not stupid," she said, "You've been gazing longingly outside all day, and this must be the eight time today I catch that bloke standing there across the street staring this way. I can see the conncetion here."

Lily rushed to the window and peered outside through the frosty glass.

And there he was – right across the street, just like Martina had said. A tall figure in black, standing still beyond the moving crowd. She couldn't see him well because of all the people between them, and a second later she couldn't see him at all.

"So, who is he?" Martina asked, "Former lover, or future lover?"

Lily didn't have the time to answer. She bolted out of the door and into the street without even putting her coat on.

"Sev!" she yelled, and didn't care who heard her. She spun around trying to catch a glimpse of raven hair or pale skin in the sea of strangers, but she couldn't see him anywhere.

She fought her way through the thick crowd and called his name many times. People were giving her strange looks and kept pushing her around, until she nearly fell down on the snow. Someone helped her back on her feet, and she made her way further down the street.

Severus wasn't there. Not anymore, if he had been there at all.

She returned to the office with a heavy heart, meeting Martina's wide eyes.

"What on earth was that all about?"

"Nevermind. I thought I saw someone I knew. It wasn't him."

Martina's eyes sharpened with interest.

"Must have been quite a someone to make you run around in the snow like that."

"Yes," Lily said, and sat down at her desk, "But it wasn't him."

The rest of her afternoon was uneventful. She felt silly for having thought that the man across the street could have really been Severus. Of course it hadn't been him – she was just making herself see what she wanted to see, and not even for the first time. She was so keen to find him that she looked twice at every tall man in black she passed by. It was deceitfully easy to imagine him standing there right within her reach.

It wasn't until later that day when she put her hand in the pocket of her cardigan and felt something there. A piece of paper, folded neatly in half, completely unfamiliar to her eyes.

The handwriting, however, was all too familiar.

Stop trying to find me.

S