Ali was going through the attic after her grandmother died. Ali found an old picture of her mother and Aunt with another girl at the lake they went to as kids. Her mother had ripped out the area the girl was in and scribbled out her name. All Ali could make of the name was the letter T. When Ali asked her mom about the picture she got nervous but denied that she knew who it was. Something felt fishy to Ali.
Ali finally convinced her mother to let her spend the summer with her Aunt and cousin Emma. Her mother was afraid that she would get herself in trouble or worse hurt. But she had nothing else to do the whole summer and her dad let her go. Ali thought something was off about how her mother was so afraid of the lake. There had to be something fishy going on.
After Ali and her Aunt got to the lake they started to see this girl Sissy. Sissy was a very rude girl. She was changing the way Emma acted and taking control of her. Ali didn't like this. Whenever something bad happened her Aunt blamed it on her. Ali had to put a stop to this. There was something that her aunt wasn't telling her. Every day she asked and there was no response.
After Sissy took Emma's doll and threatened to throw it in the river if she didn't get in the canoe Ali ran over to stop her. Emma got into the canoe and so did Ali as Sissy started to row away. Sissy threw the doll into the lake and Emma jumped in after it. It rocked the canoe and tipped Ali and sissy in. Ali saved Emma from drowning and they held onto the canoe waiting for help. After they got out Sissy told them where to find her bones so that she can rest in peace.
Emma and Ali finally found Sissy bones and let her rest. Her aunt confessed to knowing what happened to Sissy 30 years earlier. After this Sissy stopped harassing her and Emma. They had a peaceful rest of their summer. They then left feeling as if they did something good