Swamp curse

the long version

"Carter can't believe it. For the first two weeks of summer vacation, he and his younger sister, Christine, are going to have to stay with their great aunt out in the middle of nowhere. Making things even worse, their aunt lives right next to a big, buggy swamp. Carter is certain this is going to be the dullest two weeks of his life. But Carter is wrong. One night, Carter is awakened by creepy laughter coming from the swamp. Then a mysterious path appears ... and disappears. Their aunt warns Carter and Christine about a deadly swamp curse. But now the curse seems to be drawing them deep into the swamp - and even deeper into danger!"--Back cover.