James Carstairs laid face-down with his eyes closed. The familiar burned sugar smell he had come to despise wafted towards him, tinged with the scent of magic. A steady headache thrummed behind his eyeballs as unconsciousness released him from its grasp. Jem felt strong hands grab his arms and gently pull him to sitting position; his eyelids fluttered open. Though his vision was still blurred, Jem saw a pair of familiar ice-blue eyes and a shock of dark hair.

'Will!' He gasped, 'Will, wherever am I?'

The dark figure shifted uncomfortably and cleared his throat.

Jem tried again: 'Will, why does the whole room stink of yin fen? If some has got into the air then you must leave quickly before you become infected!'

'Erm...' The voice sounded odd, not like Will's at all. The slight welsh accent replaced by a full American one, 'Sorry, Brother Zachariah, I don't know who Will is- are you alright?'

Jem's vision cleared. He was propped against the wall of a cavernous hallway, which he did not recognise. The man in front of him was not Will at all; there were astonishing similarities, and yet this man's face held some of Gabriel Lightwood's haughtiness. The young man himself looked quite concerned; with that expression on his face he looked almost like – Sophie?

The young man called over his shoulder to someone Jem couldn't see:

'Izzy get Magnus quickly! Yes I know what he said… He will, trust me… For god sake Isabelle just do it!' The young man turned back to Jem, 'Sorry about that. I'm Alec Lightwood, how are you feeling Brother Zachariah?'

Jem pulled himself to a sitting position, 'I'm… quite confused actually. May I enquire as to who Brother Zachariah is?'

'Well, up until recently he was – you…' The young man – Alec – looked uncomfortable.

'I see, well I know myself as James Carstairs; Jem to most. I would prefer if, ah…'

'Of course… Jem. Carstairs? That's – unexpected.'

Before Jem could enquire as to why this was so unexpected, a door burst open and in strode Magnus Bane followed closely by a small redheaded girl and a golden-haired young man. A few moments later, Isabelle followed. Magnus' eyes swept across the room and came to focus on Jem. All at once, James Carstairs was back in London, the most beautiful girl he had ever seen stared at him with solemn grey eyes. Somewhere, Will sang raucously:

'Demon pox, oh demon pox
Just how is it acquired?
One must go down to the bad part of town
Until one is very tired'

Jem blinked and the image disappeared. Magnus Bane's cat eyes were still fixed on his face; if Jem had not been so disoriented, he would have sworn he saw tears in the sea of twinkling green. Magnus strode purposefully towards Jem but came up short at the sight of Alec, who had shrunk back into the shadows. 'Alexander,' he regarded the youth formally.

'Warlock Bane,' Alex reciprocated.

Magnus' face soured for a moment, but softened as his eyes came to rest on Jem. 'James Carstairs,' the immortal's face was awed. 'It has been too long my old friend.'

'Magnus…' Jem's voice cracked, 'I don't know where I am. I don't think I even know who I am.'

The golden haired youth from before stepped forward. Although he looked nothing like Will, something in his walk, the playful smirk playing around his mouth, sent shivers down Jem's spine. 'You're at the Institute – the New York institute to be exact. You were a Silent Brother so you're like a billion years old probably, but don't worry – you look great for your age.' The redheaded girl dug him in the ribs and he grinned at her tenderly. She shook her head.

'I'm really sorry about him, Brother Zachariah. He's an amazing shadowhunter but certifiably insane.'

The golden boy grinned, 'I am but a mad north-north west. When the wind is southerly I know a hawk from a handsaw.' Everyone stared at him. He sighed, 'that's-'

'Hamlet.' Jem interrupted.

'How did you know?'

'A friend of mine used to quote Hamlet… a long time ago. What did you say your name was?'

'Jace. Jace Waylard, Lightwood, Morgenstern, Herdondale.' The young man raised a cocky eyebrow, 'we haven't decided which yet.'

Jem's stomach plummeted, 'Herondale?'

'We have a lot of things to discuss old friend.' Magnus said quietly.

'Will? Tessa?'

The redheaded girl stepped forward uncertainly. 'Brother Zach- Jem? My name is Clary Fray. While you were unconscious, you kept repeating those two names. Will and Tessa, were they friends of yours?'

Jem surveyed her for a second. Her long, red hair fell onto her face in a way that reminded him sharply of Henry; but the defiant, wise look in her eyes was all Charlotte. 'Will is – was – my parabatai. Tessa… Tessa was Tessa.'

'Is.' Magnus murmered.

'Is? She's still…?'

'Tessa is immortal.'

Jem looked into Magnus' eyes. They were old eyes, he realised. Eyes that held so many memories, eyes that had seen too much, eyes that would never stop seeing. Magnus had the eyes of a man who was tired of what he saw. Were her eyes like that? Were those solemn, beautiful, clever eyes gone – replaced by sadness and a tired resignation? Jem prayed not. He thought of Will.

'You said Tessa is alive, but Will? He is-'Jem couldn't finish.

'Tessa is immortal, Jem, Will never was. You were there when he died… you will remember someday.'

Jem thought he felt a twinge in the old parabatai rune that was meant to be dormant. He did not remember Will's death yet, but he remembered the pain of losing his parabatai. He kept that pain with him whoever he was.

'I see… you said I was a silent brother? How long-'

'Nearly one hundred years.' Magnus replied.

'And all that time…'

'I have been what I have always been. You and Tessa meet once a year at Blackfriars Bridge.'

Jace raised his voice again. 'Will someone please explain why Brother Zachariah isn't Brother Zachariah anymore? And who Tessa is? And maybe who Will is and why, every time he's mentioned, Alec twitches like he's got a particularly bad case of demon pox?'

Jem closed his eyes for a moment before replying, 'You're just like your great-great-great grandfather, Jace.' He opened his eyes. The golden-haired boy looked dumfounded.

Magnus chuckled. 'I'll tell this story, old friend. You need your rest.'