The U.S.O or the Unidentified Swimming Object was the root cause for the disappearance of ships entering Dholakpur. The King entrusts Chhota Bheem to get bottom of the mystery, and save his trading vessels carrying gold and other valuable shippment . The boastful Kalia rushes to fight the U.S.O But fails, After Investigations Chhota Bheem & his team conclude that the sea monster appears only at dusk or nightfall. And so, they work out a plan and enter the sea monster(U.S.O) once and for all.