Zak Saturday and his parents, Doc and Drew, are a family of world-saving scientists called "The Secret Saturdays." Living in a hidden base, they are part of a secret organization of scientists known as The Secret Scientists who protect mankind against the hidden and terrifying things of the world. In the series, folktales aren't just legends, but actual mysteries that the Saturday family must solve. Traveling all over the world, the Saturdays explore ancient temples and bottomless caves, and battle with villains which includes the evil V.V. Argost (who hides his evil plans under his TV show Weird World) and rival cryptozoologist Van Rook. Scouring the globe in search of cryptids, the Saturdays attempt to keep the existence of these unusual beasts secret, to protect both mankind and the creatures themselves. The Saturdays and their exotic cryptid pets are a loving bunch, trying to work through everyday family matters and squabbles in-between their adventures.
Creator Jay Stephens has stated that the first 26 episodes will have a story arc, most likely based on the Kur Stone first mentioned in the pilot. The series was later picked up for an additional 10 episodes in January 2009.