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...