The hero of the story is Jessica, a ten year-old girl whose grandmother leaves her two cat ornaments, a tiny silver key and a letter, when she passes away.
The letter details a time in the ancient history of Earth and all planets when the malevolent Shadow Beings ruled and all beings lived in fear. A battle was fought, the light triumphed and balance was restored in the universe.
Five magical cats were appointed as the Gatekeepers of the dark realm to prevent the Shadow Beings from ruling again. One human on Earth was chosen to be the Guardian of the cats, but the location of three of them is now unknown. Only when all five cats are together are they truly powerful and able to keep the Shadow Beings imprisoned in the dark realm.
As the next Guardian in line, Jessica must face danger and the dark realm as she goes on a journey to the invisible world to find the three cats before the Shadow Beings do.
Jessica meets many magical friends along the way who help her with her quest and try to protect her from the Shadow Beings. Will Jessica find the other three cats in time? Will she be able to keep Earth and all planets free of the dark realm? Only time will tell.