Artemis is a young Shadowhunter with a dark past. She hate Clary and wants her dead along with all mundanes and her 'long lost' Uncle Valentine has found her and tried to explain her parents dead and their relation. He tries to use her to get the Mortal Instruments and a creation of evil.

Gwyn was always the black sheep of the family and basically raised by the Malfoy's and the Weasley's. Her parents could care less about their youngest child. Gwyn lied to her friends about her family and what they're like and how they truly are. Once her secret is out, can Harry and others trust her again our will the mark on her arm seal her fate? (During HBP - DH)