Several days later, Clark, Lois and Dr. Henderson are at the entrance to the Henderson caves, ready to go spelunking. The caverns are part of a river system, so the only way into the caverns is by boat. Lois and Dr. Henderson take the first boat, and Clark follows later. Inside the cave, Lois and Dr. Henderson row into a large grotto. They dock on the side of the river, but once they step out, the boat drifts off down the river. A sack of dynamite in the boat is accidentally ignited and causes an explosion that Clark, who is just entering the caverns, can hear outside. Sensing danger, Clark paddles faster.

Dr. Henderson and Lois have been captured by a race of “Hawk Men,” living in the caverns. The explosion blasted open a hole in their cave, giving them a passage to the surface. Dr. Henderson and Lois are brought before the chief Hawk Man. They see a statue of Dr. Henderson’s father above the chief’s throne. Neither of them understands why the Hawk Men have a statue like that or where they got it. The chief signals to the others, and Lois and Dr. Henderson are tied to a stone slab.

As Clark enters the cave, he sees Lois and Dr. Henderson being lowered into a giant pot of a bubbling, gold-colored liquid. Seeing the liquid, Lois looks back at the statue of the elder Dr. Henderson, and, suddenly, realizes where it came from. The Hawk Men had coated him in metal! Now they were about to do the same thing to Lois and the younger Dr. Henderson. Clark quickly changes into Superman, but before he can save Lois and Dr. Henderson, he must first fight his way through an army of Hawk Men. Once he’s finished with the Hawk Men, he saves Lois and Dr. Henderson and wastes no time getting them out of the cave. The Hawk Men chase after them, but Superman uses more dynamite to cover the entrance to their cave with rubble.

Back at the Daily Planet, Mr. White is impressed by Clark and Lois’s findings, but he feels no one would believe the story. He burns the report and the photographs taken in the caverns.

At the wreck site, the mortally wounded captain hands his secret documents to the crew’s only survivor, Lois Lane. He tells her to protect the documents with her life. Then he dies. Lois runs into the jungle and avoids capture long enough to hide the documents under a rock. She is then captured and brought back to the temple (outpost) for interrogation. When she refuses to talk, the commander orders the warriors to burn her at the stake.

Meanwhile, Clark Kent and another pilot are flying out to meet with Lois’s convoy. They spot the wrecked plane not far from the aboriginal village. Clark parachutes down to investigate. Once on the ground, he changes into Superman. He flies to the village. Lois is already being burned at the stake with the commander watching her. Just then, one of the warriors approaches the commander and gives him a set of papers. It’s the documents Lois hid in the woods. Overjoyed with success, the commander has his men radio headquarters and send the Nazi U-boats to attack the Allied fleet.

Clark arrives and saves Lois from burning to death. When the warriors see a man who can walk through fire, they run in terror. The Nazi soldiers futilely fight back against Superman. Meanwhile, Lois takes a spare white cloak and sneaks in to use the radio. The commander catches her (her ladies shoes aren’t well hidden under the cloak), but before he can do anything to stop her, Superman comes to her rescue. She sends a message to the American headquarters, warning them about the Nazi subs.

Out at sea, the Nazi subs prepare to decimate the Allied fleet. Before they can attack, they are bombed by a squadron of Allied bombers sent in response to Lois’s warnings. The subs are destroyed, and the Allied fleet is saved.

In Berlin, Adolf Hitler listens to a newsflash about the defeat of his U-boat force. Angrily, he flips a switch on the radio, and the tune Praise the Lord and Pass the Ammunition plays as the cartoon fades out.

A few days later, Clark Kent gets a call from a professor at the museum, asking him to come to the museum and listen to another theory on the death of Dr. Jordan. Clark sneaks out, but out of curiosity, Lois follows. At the museum, the professor explains that Dr. Jordan was killed by a mummy’s curse. He takes Clark through the Egypt exhibit at the museum and tells him the story of King Tush. (King Tush’s story is similar to the story of King Tut.) Lois follows them, making sure not to be seen.

Before his death, Tush’s father, the old pharaoh, commanded his giant, superhuman guards to protect his son throughout eternity. After his death, Tush became the pharaoh. Shortly after that, King Tush got sick and eventually died. Keeping their promise to the old pharaoh, the guards committed suicide, in order to protect King Tush in the afterlife.

As they approach King Tush’s sarcophagus, the professor explains that Dr. Jordan invoked the curse by trying to open the king’s sarcophagus. Clark pushes a button on the side of the sarcophagus and just misses being pricked by a poisoned syringe that shoots out at him. This new evidence seems enough to clear Ms. Hogan of the murder charges.

Sensing that the needle missed, the sarcophagus opens and a light from the dead king’s jeweled amulet awakens his giant guards (Their coffins are scattered around the room). The giant guards attack Clark, Lois and the professor. Clark is thrown into a sarcophagus, where he quickly changes into Superman. As Superman, he defeats the giant guards and saves Lois and the professor from a grime demise.

Back at the Daily Planet, Clark smiles as he finishes his report on Ms. Hogan being released from jail. Lois is sitting on the desk. She was injured in the mummy attack and her hands had to be bandaged up (therefore, she wasn’t able to write the story herself). She grumbles as Clark finishes his story. When Clark asks how she knew to be there, she replies, “My mummy done told me.”

Lois goes undercover as a factory worker. One day, during her shift, she overhears the foreman telling several of the workers that Mr. Jones, one of the supervisors, wants to go over the plan. During break time, the workers head up to Mr. Jones’ office. Lois follows. Up in the office, Lois overhears Mr. Jones’ plan to blow up the factory. The switch to the factory’s night lights has been rigged to a case of dynamite. When the night guard throws the switch, the whole factory will explode. Just then, Mr. Jones sees Lois outside the office window. He sends the workers to catch her. Lois manages to get away from the workers, but is caught by the foreman. The night guard enters the room and rushes to help Lois. The foreman stops the night guard by dropping several tons of scrap metal on him.

To silence Lois, the workers load her into a test torpedo with another case of dynamite. (As a company rule, test torpedoes aren’t loaded with explosives.) The torpedo with Lois is sent to the testing range and set to be fired at a dummy ship. Back inside the factory, the night guard is struggling to free himself from the rubble. The night guard is really Clark, who has also decided to go undercover. Under the rubble, Clark changes into Superman.

As the test torpedo is fired, Clark rushes out to the testing range and saves Lois before the torpedo explodes. Realizing that they’ve been discovered, Mr. Jones orders the foreman to throw the night guard’s switch now. He reaches the switch, but Superman stops him from throwing it. Just when Mr. Jones thinks his plans are ruined, he spots a truck loaded with dynamite. He steers the truck toward the factory in a collision course, then jumps out before impact. Lois warns Superman, who was previously pinned down by the workers, about the truck. Superman catches the truck and sends it over a cliff, saving the factory.

The story ends with Mr. Jones, the foreman and the workers being arrested, and Lois revealing that she knew Clark was the night guard. It may have been meant as a subtle irony that Lois was able to see through this disguise easily but could not figure out that Clark was Superman as well.

At the opera, the Superman imposter sneaks from booth to booth, swiping people’s jewelry without them noticing. When one woman cries out in alarm, Lois leaves her seat and walks out into the hallway, confronting the imposter. After a brief struggle, Lois rips the “S” patch off the imposter’s chest, and he runs away. Not having seen his face in the darkness, Lois is convinced that Superman has really been responsible for all the crimes, concluding, “It is Superman.” Lois sits down in front of a nearby phone to call the police, and Clark exits the booth to follow after the imposter.

Cracking the door open slightly on the roof and noticing the imposter, Clark says, “My double is in for some trouble.” Seeing the police cars gather on the street below, the imposter heads back toward the door to the stairwell, where he is confronted by the real Superman. The imposter fires several rounds at Superman, to no avail. Out of bullets, the imposter becomes frightened, and walks backward as Superman approaches. In one final attempt, the imposter hurls his gun at Superman, which bounces away without causing damage. Without noticing, the imposter reaches the edge of the rooftop and falls over the edge. Superman swoops down to save him just in time. In the glow of the search lights, Lois and the police realize that the real Superman is not the criminal.

Hoping for a lighter punishment, the imposter agrees to take Superman to his boss. Superman, without saying a thing, stands in front of the boss’ desk. After several moments, the boss shines raises a lamp to see Superman’s face. The boss presses a hidden button that opens a trap door and sends Superman falling into a pit. After the trap door closes, the boss and imposter push the desk over the door and hide in a vault. Superman breaks out and opens the vault, only to find that the two have used a welding torch to cut a hole in the wall and escape. A police car is headed around a bend, unknowing that the mob boss and imposter are coming at them from the other side. Just in time, Superman steps in and stops the cars from crashing, and he leaves the two criminals for the police to handle.

Back at the Daily Planet, Clark is dozing off when Lois returns from the crime scene to start work on the story. Clark tells her that he was dreaming he was Superman. Lois responds by saying, “A fine Superman you’d make.”

As the plane takes off, we see that there are other stowaways aboard. Hidden inside what look like bombs are three Japanese spies. The spies tie and gag the pilots and hijack the plane. Meanwhile, Lois emerges from her hiding place and sneaks over to the cockpit. As she’s about to open the door, she notices that the Japanese spies have hijacked the plane. She sneaks into the room and calls for help on the radio. In response to her calls for help, fighter planes are sent to stop the hijackers. In response, the hijackers deploy a bomb, which stops the fighters from taking off. Clark Kent goes into an elevator and changes into Superman as it goes up to the roof.

Superman enters the plane to stop the hijackers, but one of them has Lois tied up and is ready to drop her out of the plane through the bomb hatch. Superman jumps out of the plane and comes back in through the bomb hatch to save Lois. He unties her and then starts fighting the hijackers. One of them breaks the plane’s controls, and the plane starts falling towards the city. Superman takes Lois out of the plane and places her on the ground, then flies back up and catches the plane, bringing it to a safe landing right in the middle of the street.

Circus workers attempt to tie the ape down with ropes, but are overpowered but its strength and are forced to flee. While other workers are struggling to keep the other animals under control, some of them stampede, or rear up against their owners, knocking other cages open. Lois, who has been taking pictures of the ape, is about to leave when she notices the monster lumbering toward a trapped young girl. She runs between the creature and the girl, and helps her escape, only to have the ape turn on her.

Clark arrives on the scene, supposedly to pick up Lois, and sees the chaos. Quickly he changes into his Superman costume and begins setting animals in their cages. Right after tossing an elephant into a cart, he hears a scream: Lois is trapped at the top of a pole holding up the tent, and the ape is climbing perilously close. Superman confronts the ape and ties it down, but during the fight one of the tent poles falls down and hits a power circuit, starting a fire. Superman saves Lois from the flames just in time. The final scene shows Lois vigorously typing the story, with Clark sitting lazily back in a chair at the next desk.

On arrival, Clark can’t find his press pass (Lois has it hidden in her purse), and goes back into town to retrieve it as Lois takes a tour of the volcano. Her guide tells her that the plan to save the city is to blow a hole in the side of the volcano, thus altering the course of the lava flow from the town, to the ocean on the other side of the island. Suddenly, the volcano begins to erupt, and lava spews out of its top, flowing towards the town. Lois and her guide are separated. Two men on the other side of the volcano scramble to get to the machinery which will blow a hole in its side, but a giant boulder cuts the wire connecting the dynamite to the machine, rendering it useless. From the town below, Clark sees the volcano let out a particularly explosive blast and says, “This looks like a job for Superman.”

He changes into his costume and flies up to the volcano, catching a huge boulder hurtling toward the town and flinging it into the ocean. This momentarily leaves him stunned on a ledge on the mountainside as the lava creeps nearer and nearer to the town and Lois is struggling to get away from the volcano by edging hand over hand along a cable wire connecting two mountains. She makes it to a cable car just as the cable begins to give way. Superman saves her, then flies back, catches the cable car and flings it at a mountain near the advancing lava, causing a landslide which dams up the lava flow to the town. Then Superman flies to the dynamite machinery and notices the cut wire. He pulls the two wires together to complete the connection, and in a huge blast the side of the volcano explodes, and the remaining lava slides harmlessly into the ocean.

In the final scene, Lois and Clark are on the boat home, and Clark commends Lois for her excellent story. Lois remarks that its too bad he wasn’t there as well, whereupon Clark pulls the second press pass sticking out of her open purse and says, “I would’ve been, if I hadn’t lost my pass.”