Tessa stared across the clearing. Alicante, the Glass City, looked almost exactly as it had when she'd left it only minutes before. Nearly two hundred years in the future, she was surprised to see it looking so unchanged. The only difference was that Angel Square, next to the Accords Hall where she'd left Charlotte behind, was flooded with people.

"Drinking it all in?" said a quiet voice.

Tessa whirled around and saw Magnus Bane, wearing a shockingly normal-looking coat and trousers. He was leaning against a tree and eyeing her with an inscrutable expression.

"I just left this place," she said to him, eyes roving the clearing. "And nothing looks different."

Magnus gave an eloquent shrug. "Idris is not a country of change. Although we've seen quite a bit of it in the past few weeks."

Tessa decided not to ask what he meant; that was not what she had come for. But she found she didn't quite want to ask the question yet. She was reluctant to admit to herself that the answer may not be what she wanted to hear.

Instead she looked out over the square, taking in everything. There was a lot to see, but she found that her eyes kept returning to the same two people: a short, redheaded girl and a muscular blond boy. The two were holding hands and obviously in love, but that wasn't what held her gaze. The boy looked so familiar she felt that she must know him, though she knew she had never seen him before - after all, this was a later time period. And his eyes were positively unusual - a luminous amber that shone like gold when he turned towards the setting sun.

"Admiring? I'm not surprised, most people do," Magnus told her. "Clary's a lucky girl."

"Clary? Is that the girl with the red hair?"

"Yes. Clarissa Morgenstern."

She waited, but that was the only answer she got. He seemed to be avoiding telling her something.

Tessa turned back around to look at them. The boy laughed, and again she felt like someone she had once known was staring her in the face and she was unable to recognize them.

"Who is the boy?"

Magnus raised his cat eyes to look at her. He was smiling in amusement. "That's the boy who only recently killed Valentine's son and spy, fell in love with the wrong person and who survived to see a happy ending."

Tessa set her jaw. "Would it trouble you too much to give me a name?"

Magnus huffed in annoyance. "Well, if it bothers you that much. I was planning on dragging it out for a while, but if you insist…that's Jace. Jace Herondale."

Tessa froze. All she could think about was that Herondale was Will's last name, and that he had no other family to carry it on. So then…

"Will," she breathed. "Will's child."

"Not Will's exactly," Magnus said. "That would be impossible, seeing as the two of you are living two hundred years in the past from Jace. But yes, they are directly related."

Tessa's breathing was ragged. "And who - who was his mother?"

Magnus looked at her with something like pity. "Celine Herondale."

"You know what I mean."

The warlock sighed. "I know what you mean. And did I not just say 'the two of you'?"

It took a moment for the words to sink in. When they did, Tessa felt as though she was finally thawing after a long, deep frost. "Me."

Magnus directed his eyes heavenward. "Again, you're not Jace's mother because that would be highly theoretically improbable. But you are something like his great-great-great grandmother on the Herondale side."

"Which means…"

"Yes. Go back to your own time. Someone's waiting for you. And someone's waiting for me." As he said this, he looked over towards Jace and Clary. Turning, Tessa saw a tall boy in a brown sweater with sweeping black hair and blue eyes. Magnus's expression when he looked at the boy made her want to laugh out loud, but at this moment there wasn't anything that didn't make her want to erupt with joy.

As she prepared to Mist, she locked eyes with Clary. Clary looked at her curiously, and Tessa smiled at her. She knew that Clary would be happy, just as she would be happy as well. She closed her eyes, and the Glass City melted away. But she knew that unlike the last time she'd Misted, she had something to go back to. Someone to go back to. And he was waiting for her, back where she belonged.

EPILOGUE

Tessa looked down into the courtyard of the Institute, where two dark heads stood out vibrantly against the green of the grass. One was larger than the other, bending down into the smaller one.

"Say, 'Shadowhunter'." the larger one said. "Say 'seraph blade'." At this, he pulled out a short, sharp blade and pretended to hand it hilt first to the younger one.

"Will," Tessa said reproachfully, descending the stairs. "It does not seem wise to hand daggers to two-year-olds."

Will Herondale stood up. His gorgeous eyes were sparkling, and again Tessa was reminded of the extraordinary change she'd seen in him the past few years. Becoming a husband and father seemed to have cured him of the ghosts of his past for good. "He's a Shadowhunter, Tess. The knowledge of how to use these is in his blood."

At this, baby James squealed happily, as if agreeing with Will's statement. Tessa bent to the grass and swept him up into her arms. "Jem, you do not have my permission even to touch a seraph blade until you're at least ten," she told her son, feigning seriousness. He stared back at her with his huge, extraordinary amber eyes, lit to gold by the sunlight. Even though it had been two years since she'd seen Jace, when her son had been born she'd recognized his eyes immediately. Charlotte, Henry and Jessamine had all expected his eyes to change, the way babies' eyes did, but Jem's had not. Tessa had known they wouldn't, and Will had expressed his confidence that he didn't think they would change either. He'd put the thought down to a gut feeling, but Tessa thought it was more like family intuition. And now, two years later, nothing about him had changed, like they'd predicted. He was Will in every way, but for the eyes blinking out of his face. And his moderately more innocent expression.

"Ten years old is a little late, don't you think? Maybe five, or six. I expect him to have killed his first demon by the time he's ten." Will came over and wrapped his arms around Tessa's waist, gazing intently into her eyes. He always looked at with the same bright, burning look that Tessa had realized two years ago was filled with love: in Angel Square in Alicante; they day they'd married; the day Jem was born.

She rested her head against his forehead, feeling the electricity run through the two of them. Her small family, the people she loved most in the world, were here with her: Charlotte and Henry, godmother and father to her child, Jessamine, who had remained a Shadowhunter and fallen in love all at once, Jem senior himself, healing away in Shanghai, her own baby Jem, between her and her husband now.

And Will. Always Will. Looking his face up and down, she smiled secretly to herself. There was no need to worry that his beautiful eyes would be lost to the centuries. She'd done a little more exploring into the future than she ought to have done, about seven years after she'd seen Clary and Jace together in Alicante. Will's eyes reappeared in Clary and Jace's child, a girl, tall with a cloud of brown hair. Just like Tessa.

But when Will leaned in to her, she forgot all about their future generations. Their lips met, and the world around her seemed to fall away, melting into the background. Three heartbeats paced in time with her own: Will's, Jem's and the clockwork angel's, now hanging around her neck. She knew they would remain forever. And as she and Will kissed with growing intensity, she knew also that the fire between them, and in the rest of her life, would last forevermore.