Daisy Campbell made a promise to her sister's grave; finding out who murdered her. The police lied about the placement of the knife that caused Elaine's death. They placed the knife in her hand, when it originally was in her chest. After stating that it was a 'suicide', the police called off any further investigation, closing the case. But Daisy knew what she saw, no matter how much the police tried to convince her otherwise. And after switching to Elaine's school, Daisy found out how right she truly was. Because Elaine's murderer didn't seem to take it very well that Daisy was trying to uncover the truth.