Professor Schultz uncovers a living dinosaur in suspended animation frozen in a block of ice and transfers the brain of his assistant into the body of the monster in order to wreck American munitions plants. The assistant's sister goes looking for her brother, and when she trips and falls in front of the beast, the creature avoids stepping on her on purpose. Cap realizes what must have happened and delivers a lecture about serving one's country to it. It gets through to the man's brain and the dinosaur turns away from destroying the munitions plant and pursues the professor. The creature throws the professor to his death in a ravine and, after taking one last lingering look at his sister, plunges to its death in the ravine as well. Cap and Bucky tell the girl that her brother died bravely fighting for his country.