Brother Jeremiah is called upon by Hodge Starkweather to assist Clary Morgenstern in regaining her memories. He states that he cannot break the block set on her mind alone and that she must accompany him back the the Silent City to get help.
At the Silent City, it is revealed that only the one that put the block on her mind could undo it and that that person was Magnus Bane. Brother Jeremiah then leads Clary out of the Silent City.
Brother Jeremiah is next seen when Jace Lightwood is in prison. He is in a holding cell of the Silent City and he hears screams from above. Brother Jeremiah opens the door, having been attacked by Agramon, and fell dead on the floor.
Brother Jeremiah had pale skin, littered with runes. They were described as black markings across his white skin. His head was shaved and was said to look like an egg. He had no eyes, just indents where they should be. His mouth was sewn shut, signifying that he didn't need to speak.
Powers and Abilities
Brother Jeremiah possessed an array of powers.
Mind Reading: Brother Jeremiah possessed the ability to Read the minds of those around him.
Runes: As a shadowhunter, Brother Jeremiah possessed the ability to bear the marks of the angels
Stele- Brother Jeremiah possessed a Stele, which he used to draw runes