Russel is surprised to discover a secret passage, Whenever the Wright family goes to their new residence. This passage leads him and his dog Gus to the world of Underneath, where he discovers he may be the King that is brand new and that Gus will talk! Russel and Gus befriend creatures and the people of the mysterious territory. Become allpowerful rulers of their territory and also his team that is wicked and bob Wire are conspiring to slip the crown of Russel.