Stabler and Benson investigate the murder of a 15 year-old girl who was using her 21 year-old cousin's ID to live the older lifestyle. They find Lisa, this not-so-innocent teen, was wrapped up in a world of teenage prostitution, where she and her friends trade sexual favors in exchange for money and expensive clothing. To complicate matters, they find that she was HIV positive, and was having unprotected sex in pornographic films.