Jeremy Pontmercy was the youngest member of the Circle.
Jeremy was very young when Valentine Morgenstern recruited him, though he grew to become very loyal. Some years after, when he was around fifteen, Jeremy attended the wedding of Valentine and Jocelyn Fairchild and congratulated them.
Sixteen years after the Uprising, Jeremy joined his late leader's son, Jonathan, in a similar endeavor and became one of the first Endarkened Shadowhunters after willingly drinking from the Infernal Cup. Shortly after, he had a brief confrontation with Jocelyn, during which he tried to convince her to join them, and was killed by Maryse Lightwood.
Jeremy had a pinched face and livid scar along one of his cheeks.
- City of Lost Souls (first and only appearance)