How do you succeed where a legend failed?

Eighth-grader Penny Preston thought she knew how to handle the Bodach, spirits from the 5th dimension. But when a primordial power threatens to tear the fabric of the multiverse, higher-dimensional energy seeps into Piper Falls, New York, and re-energizes the Bodach and their powers.

Unleashing havoc , their attacks draw three others to the small town—an ancient commander seeking revenge for her defeat by the King's Blade, an ethereal Celtic spirit with a taste for exotic nuclear particles, and a shapeshifting spy.

Penny and her friends must again dodge detection, as they sort out the intentions of these powerful entities. How can she succeed where King Arthur failed when one wrong step risks unleashing the apocalypse?