Shari and her friends all subscribe to 'Dixi' - a Facebook like social network for tweens. This is the place where they post updates on what they're doing, share their thoughts, play games, take part in online polls, upload photos and videos, etc. Shari learns that her profile has been hacked - photos defaced, embarrassing, crude insulting updates added. Not only that, but Shari has been locked out of her own account. But Shari won't give up and simply start a new profile - she's going to get her page back AND find whoever did this. But when her friends' pages start getting hacked they realise that there's a cyber 'serial killer' on the loose.