After their father's disappearance, Jonathan Hatter and his sister Jillian are sent on vacation to visit their grandmother, Nora. While there, they learn something incredible. Apparently, the hats in their family shop are not just for fashion. They are a means of time travel, and it turns out Jonathan and Jillian are related to a community of Time Travelers known as "The Hatters."
Their real adventure begins with an article in the local San Francisco newspaper, claiming that Egyptian artifacts-including the crown of Pharaoh Seti-are missing from a highly secure area of the British Museum. The brave, young siblings are now on the hunt for Chi, a despicable Hatter who has fallen from the ranks and stolen the Egyptian items in question.
Chi has used the secret Door of Osiris to transport the stolen artifacts, but while searching for Chi, Jillian slips on the crown of Aset and is transported back to 1300 BC Egypt. It's up to Jonathan to go back in time, help his sister, and return the pilfered treasures. First, they must battle giant crocodiles and colossal stone guardians. They will meet Osiris and the mystical goddess Aset as they weave in and out of grand palaces, dungeons, and even the underworld.