Gone, But Not Forgotten

Growing up, Xander, Damiano, Ezra, and Luna became known as "The Pack". They got their name for being like wolves that move in a pack. Luna gets caught up in the middle of a mafia issue. This leads to her untimely death... At least that's what they thought.
She spends her time away at a training camp where she became apart of an elite assassin organization, the Trojans. When the Trojans begin their training, they have to shed their identities including their memories.
Xander, Damiano, and Ezra find her in the middle of a mission. When her path crosses with the Pack again, it's under different circumstances. She has no recollection of them at all.