Robert Saunders wants to build a sub-oceanic tunnel from North America to Europe. He discovers a gentle underground civilization and he destroys the tunnel to protect them from the upper world.; Scientists find a seemingly primitive man, but they discover that he is really from a future where nuclear war has destroyed civilization.; A diver tries to capture mermaids to sell them to zoos, but they capture him instead and place him in an exhibit.; A scientist puts off marrying until he is wealthy because he wants to avoid the mistake of his parents always arguing since they were poor. He becomes wealthy by inventing a matter duplicator device. When the girl he wishes to marry steps in front of the device, there are now two of them, arguing over which one of them gets to marry him.