After a brief synopsis of Thor’s origin, the story opens with Dr. Don Blake and his nurse Jane Nelson (later named Foster) on their rounds of patients. Don is in love with Jane but fears that if he said something she would quit and he would never see her again; meanwhile, we discover that Jane loves Don and longs for him to show some affection. When the news reports on a revolution in the Latin American nation of San Diablo, Don and Jane both join a team of medical personnel volunteering to care for the war victims. As their ship nears its destination, planes dispatched by the Marxist dictator known as the Executioner attack. Don Blake quickly rushes off to change into Thor; he flies into the air, smashing the jets with his Uru hammer and allowing the pilots to parachute to safety. Dropping underwater, Thor stamps his hammer on the hull of the ship and changes back into Don Blake, claiming to have fallen overboard during the excitement.
In San Diablo, the Executioner orders the commander of his air force taken to the wall and shot. Elsewhere, as the American medicos walk through a mountain pass, they are fired upon by snipers; Don calls up a thunderstorm, blinding the enemy and causing them to become mired in the mud. As the doctors emerge onto the plain they spy tanks heading toward them. Changing to Thor our hero uproots a tree to use as a lever to flip the tanks around, reducing them to junk. All the Americans escape...except for Jane who is captured and taken before the Executioner. Thor follows as Don Blake and demands that the tyrant release her. The Executioner seizes Don’s cane and orders him shot; Don goads the villain into coming closer, then snatches back the cane and raps it on the ground becoming the Thunder God once more with a flash that blinds all witnesses. Thor hurls his hammer, retrieving a huge tent and drops it on the soldiers. The democratic forces arrive and engage the Communists in battle. The Executioner is caught trying to flee with the nation’s treasury and he is shot by his own men before the wall where he ordered so many others killed. Later, their mission over, the medical team can return to the States; Don explains his absence during the action by claiming he was hiding behind the execution wall the entire time and Jane wonder why he can’t be more like Thor.