Third Person Pov,

" What is going on ?!" Jace demanded, as he stomped into the New York Institute .Today, he was having a date with Clary when there was tingling felt at the rune of his shoulder. His Parabatai rune. After the tingling, a wave of sadness hit him, and he starts to feel dizzy. That can mean one thing.

Alec.

Izzy met Jace at the door of the Institute.

"Jace? I thought you are on a date with Clar-"Before Isabelle can finish her sentence , Jace cut her off.

"Where is Alec? " Jace demanded.

Isabelle was shocked at Jace's tone. Jace rarely snap at her even when He used to think that Valentine was his father and there is demon blood in him. Now he knew he is a Herondale and can better control his temper but yet he snapped at him.

"Alec just went out. Why?"

"Quick, we must go after him. "

"Jace,I know Alec is your parabatai and you vow to always protect him. But, you should give him some me time. Plus, there is Magnus. Magnus is the high warlock of Brooklyn and I can tell that Magnus love Alec dearly."

Even though it sound convince to Jace, but the Parabatai rune tells him otherwise. The parabatai bond radiates sadness , bitter,fear, and something familiar.

Heartbreak.

"No Izzy, this time is different. I am feeling something wrong Izzy, you got to help me." Jace pleaded as he put his right hand on his collar,where the Parabatai rune is .

After a moment of hesitation, Isabelle finally nodded.

" I don't know where Alec went. Honestly. Maybe we can go to Alec's room. There may be some clues in his bedroom that can tell us where Alec is now." Isabelle suggested.

Immediately, the two young Lightwood siblings ran up the stairs of the Institute to the room of their eldest sibling.

When Isabelle and Jace reached Alec's bedroom, Isabelle was about to kick the room open when Jace suddenly stopped her. The parabatai bond seem to tighten a little as a voice appeared at the back of Jace's head.

Open this door. It is Unlock. The voice seems to say. The voice seems too familiar. It was Alec's voice.

Jace reached our and turned the doorknob. Guess what, the door was unlock. To Jace and Isabelle , this is a bad thing .

Alec . Leave his door unlocked.

Isabelle and Jace looked at each other before rushing in.

Something was not right.

When Jace and Isabelle rushed in, there was a letter on the immediately ran towards the bed and picked up the letter, with Isabelle close behind him.

The letter said:

Dear Jace,

When you are reading this, I have already left for the Silent City. Don't blame Izzy, I am the one who have decided to do so. Make sure Izzy don't blame herself too. I know we are parabatai and we vow to protect us till death do us part but I have met so many challenges in my 20 years of life. I need some time to just calm down and I think the Silent city is the best , I am useless Jace. I feel sorry to be your parabatai.

I know I am being selfish. I am sorry Jace.

And tell Magnus that I am sorry for leaving Magnus that I met with Camille to ask her about his life. I never want to take his immortality.I will always love him. For centuries and centuries to come.

Tells Isabelle that I am a horrible big brother and a useless one. I can't even protect her like a big brother should and we always argue because of it.I am sorry. I know that a sorry will not make up for what I have done. I don't seek for your forgiveness, I just wish for your understanding.

Best Wishes,

Your Big Brother.

Alexander Lightwood.

Tears rolled down Jace's cheeks as he read the letter, with a crying Isabelle in his arms.

Oh Alec! How can you be so stupid. You are the best Parabatai I can ever have! Jace thought. Then , there was a sharp pain at his Parabatai rune. Jace immediately yelled , clutching the parabatai , Jace's knees felt weak as he fell onto his knees. He could hear Isabelle calling his name but all the feeling around him felt distant. All he can feel the Parabatai rune at his chest getting tighter and ..

Snap! The parabatai bond snapped like a string of life being cut.

Jace suddenly felt empty, seems like there is no more support that bind Jace to his sanity. It was Alec who binds him to sanity and now sanity is gone along with Alec. Jace removed his hand from his collar. He looked down at a hand with blood.