Meet the Sinister-Winterbottoms: brave Theo, her timid twin, Alexander, and their older sister, Wil. They're stuck for the summer with their Aunt Saffronia, who doesn't know how often children need to eat and can't use a smartphone, and whose feet never quite seem to touch the floor when she glides-er-walks. When Aunt Saffronia suggests a week pass to the Fathoms of Fun Waterpark, they hastily agree. But the park is even stranger than Aunt Saffronia....

In the mid 1800s, Pyncheon is still a revered namesake in Salem, with the gloomy Pyncheon mansion serving as a stark reminder of the family's upper class history. However, the house, unique for its seven gables, has a dark and deadly past. Its current occupant, the older and unmarried Hepzibah Pyncheon, is all but destitute and unwilling to accept any assistance from her wealthy but unrelenting cousin, Judge Jaffrey Pyncheon.