Commentary Superman II is the first of three sequels to the 1978 blockbuster Superman, starring Christopher Reeve as the Man of Steel. In this sequel, the three arch-villains from the beginning of the first movie escape and wreak havoc on Earth until Superman can stop them. This movie has all the elements of adventure, romance, and Sci-Fi which made the first movie great, as well as all the lead actors, plus a few more.
Introduction: Some terrorists seize the Eiffel Tower and plan to detonate a hydrogen bomb. Chief Perry White of the Daily Planet sends Lois Lane out to report on the incident. When Clark hears of this, he removes his disguise and flies off as Superman to save Lois and send the bomb into space. Unfortunately, the explosion causes the Phantom Zone which is used to imprison the three arch-villains General Zod, Ursa, and Non from Krypton to break, freeing them.
Superman and Lois: As usual, Lois Lane suspects that Clark Kent is really Superman in disguise. Eventually her suspicion is confirmed and she declares her love for him. The two fall in love, but Superman must forego his superpowers in order for the relationship to work.
Reign of Terror: As soon as the three arch-villains are freed, they cause hoards of trouble. First they sabotage a lunar mission, killing all three astronauts on the moon as well as destroying the lunar module. Then they make a mess of a small town in Idaho and threaten to do the same with the rest of the world unless the President of the United States (Marshall) steps down and usurps his power to General Zod. He does so, bowing and kneeling before Zod, but tells him that Superman will never bow down to him.
Superman Returns: Once Superman (now as Clark Kent, without any powers) learns of the reign of terror, he returns to his fortress on the north pole and begs his father Jor-El to give him back his powers so he can fight the enemy. He is able to do so and returns to Metropolis, where now Lex Luthor has handed Lois Lane over to the villains in exchange for Australia. The confrontation results in an awesome superbattle throughout Metropolis. Ultimately Superman loses the battle though and flies back to his fortress.
Defeat of the Arch-Villains: The arch-villains kidnap Lois and Lex and take them to Superman's fortress. Superman then battles them again, but the villains threaten to kill Lois unless he backs down. Eventually Superman devises an ingenious plan to defeat them however (I won't give away any details here!)
Conclusion: It turns out that the only way Superman can retain his powers is if he ends his romantic relationship with Lois, which he does with a kiss that makes her forget it ever happened and that he's Clark Kent. Disguised as Clark Kent, Superman gets even with a thug who'd bullied him at a diner earlier after he'd lost his powers. The movie ends with him apologizing to the President for letting him down and placing the roof back on top of the White House.
An Astronomical Coincidence
One beef I've always had with this film is that the Phantom Zone which holds the arch-villains just happened to be in the vicinity of the Earth when the hydrogen bomb goes off. What are the odds against that? Assuming the Phantom Zone is near the moon, which is a mere 240,000 miles away from the Earth and that Krypton is in another galaxy, presumably at least a million light years from the Milky Way, the odds are roughly the cube of the ratio of these distances, or approximately one in 10^40, or 10 followed by 40 zeros! It's more likely that you'll win the lottery five times in a row, or that you'll be dealt six royal flushes in a row in poker.