A children's classic and bestseller, Pierre Berton's The Secret World of Og has the other-worldly aspect of "The Lion, the Witch and the Wardrobe", together with thematic elements of the "Indian in the Cupboard". It's a coming of age story about four siblings, Penny, Pamela, Patsy and Peter, who discover a cavern beneath their clubhouse floor. A tapestry of adventure and imagination, the animated series starts with the Berton kids' inaugural journey to locate their lost baby brother (Paul or "Pollywog"), and continues on, along the underground river, as they explore, investigate, and attempt to solve mysteries along the way.