It's The Mortal Cup Jace,

I Would Have Given It Up--all Of It Up--to Be Married To You For A Day. A Day That Would Never Have Come. You Are A Reminder--a Reminder Of Everything I Am Losting. The Life I Will Not Have.

Magnus Had Learned To Be Careful About Giving His Memories With His Heart. When People Died, It Felt Like All The Pieces Of Yourself You Had Given To Them Went As Well. It Took So Long, Building Yourself Back Up Until You Were Whole Again, And You Were Never Entirely The Same.

There Are Some People—people The Universe Seems To Have Singled Out For Special Destinies. Special Favors And Special Torments. God Knows We're All Drawn Toward What's Beautiful And Broken; I Have Been, But Some People Cannot Be Fixed. Or If They Can Be; Its Only By Love And Sacrifice So Great That It Destroys The Giver.

But Magnus, He Thought. You Never Told Me. Never Warned Me It Would Be Like This, That I Would Wake Up One Day And Realize That I Was Going Somewhere You Couldn't Follow. That We Are Essentially Not The Same. There's No "till Death Do Us Apart" For Those Who Never Die.

She Had Never Imagined She Had The Power To Make Someone Else So Happy. And Not A Magical Power, Either--a Purely Human One.