Trix came from Sector 5, and thanks to Dom (an ex-O'Kane) she was kidnapped and brought back. To everyone in 5's surprise, it turns out that Trix was actually Tracy; Tracy was basically next in line to be Mac Fleming's personal toy before everyone assumed she overdosed...including Finn, her boyfriend. Instead, she got clean and escaped to 4, changed her name, and never looked back.
For years Finn has been living a shall of a life. He has a personal vendetta to take Mac Fleming and Sector 5 down. He always felt guilty about Tracy's death; he wasn't strong enough to save her from her addiction, and as Mac's top seller, he had to live with the fact that he was not a good guy. He was a villain, and he wasn't living to make a future for himself, he was living to take down Mac Fleming. That is, until he saw Trix for the first time in years. Alive.
After that, he had a new mission: Get