Mr. Freeze is back in town, and has plans to build an icy weapon that will have the world at his control. With help from Glacia Glaze, the renowned ice skater, he captures Professor Isaacson and tries to extract the secret formula for instant ice from him. Mr. Freeze then sends his trained seal Isolde to Police Headquarters with a note, demanding Batman deliver a ransom in exchange for the professor. But the frosty villain not only plans to keep the money and the professor, but to terminate the Dynamic Duo in the process.

Back in his iceberg headquarters, Mr. Freeze persuades the kidnapped Professor Isaacson to build him a thermodynamic ice ray beam. He issues an ultimatum that he will begin freezing the entire country if his demands are not met, then gives a demonstration of his weapon. As the villain works out just what his demands are, Batman and Robin track his seal, Isolde, through an ice-packed Gotham Harbor to locate the villain's hideout.