I wrote a sequel treatment (not a script) several years ago to Superman 2 that started with Clark Kent and Lois Lane trapped in a bank vault because of Clark's klutsiness. The vault goes on a time release mechanism and they are stuck in the vault until morning, roughly 10 hours until the manager arrives and opens the vault. A lot of witty banter ensues with Lois blaming Clark and Clark being sweet to Lois. Clark talks about his happy childhood in Smallville. He really misses his dad. He speaks about how his dad died in his arms and how powerless he felt. Lois talks about her rough childhood, moving around alot, she was an army brat and doesn't have many real friends. She never felt like she had a home. We really get to see some genuine human moments between the two star-crossed lovers. Lois begins to realize how important Clark is to her. Clark is obviously head over heels with her. Meanwhile all hell breaks lose when a new villain with similar powers to Superman arrives in Metropolis. He's been tracking a kryptonian heartbeat from the outer reaches of space. The villain is Braniac. He begins tearing Metropolis apart when the kryptonian heartbeat suddenly goes silent. Don't forget, supes is trapped in, of course, a lead-lined vault. Braniac proceeds to cause as much havoc and destruction in order to call out the kryptonian, whom he believes is in hiding. Because of the chaos in downtown Metropolis, the bank in which Clark and lois are trapped doesn't open that day (everyone is warned to saty out of downtown Metropolis). Thus, Clark and Lois are trapped for longer than 10 hours. Because the vault is vacuum sealed, they begin to run out of air. Clark must choose between seeing Lois die or divulging his heroic identity. The choice is easy. Lois is losing consciousness when Clark finally decides to rip open his shirt. But the bank door rips open right before Clark reveals his identity. Instead, a group of crminals taking advantage of the chaos caused by Braniac decide to rip off the bank. Lois faints. Supes springs into action stops the burglars and exits the bank with an unconscious Lois in his arms only to see Metropolis in ruins. Think the crumbling cityscapes witnessed briefly in CONSTANTINE (keanu's cool flick). Sunny Metropolis looks like dark Gotham. Buildings are smoldering. People are dead in the streets. Cars wrecked. Superman is devastated. How could this have happened in such a short time?
Meanwhile, Lex is in jail. He escapes, complicating things further. Lex heads to the fortress of solitude in an attempt to learn more about Superman. Instead, Lex discovers the ghost or essence of General Zod at the fortress. Zod's ghost posseses Lex Luthor and endows him with incredible powers. Super Luthor returns to Metropolis with the goal of killing Superman. Instead Braniac believes Super Luthor is the last Kryptonian. Thus, Luthor proceeds to get his ass kicked by Braniac. Superman arrives and a massive battle ensues in which Supes and Luthor are forced to team up to destroy Braniac.
Braniac's backstory is that he and the rest of the kryptonians knew that by going to earth, kryptonians would become powerful Gods. Braniac advocated invading earth and taking it over. The Krypton council were a peaceful people and enacted a law forebidding kryptonians from going to earth. Braniac attempted to escape krypton in a stolen ship and head to earth. The ship was shot out of the sky by Jor-el. But Braniac escaped in an escape pod. But the pod froze in deep space and was lost in space for several years. He finally crash landed on an alien planet, consructed a new ship and headed to earth to destroy the son of the man who shot him down--jor-el.
Anyway, in the end Luthor with Superman's help (because he is human and not kryptonian, Lex is immune to Kryptonite) uses kryptonite to destroy Braniac. We think that a truce has finally occured between Supes and Luthor but of course once the threath of Braniac is over, Luthor viciously turns on Superman. You can never trust Luthor. Superman, heavily battle scarred, retreats to the fortress of solitude. Luthor follows. A final battle ensues amid the arctic mountains. Superman emerges from the fortress wearing an armored lead-coated endoskeleton suit. A massive battle ensues and Superman finally pounds Luthor into submission. In the end Superman places Luthor in the molecule chamber and the essence of Zod is forever vanquished.
The final scene has Lois frantically searching for Clark in ravaged downtown Metropolis. She thinks that he was killed in the destructive battle of Metropolis. Clark shows up with torn and tattered clothing. Lois jumps into his arms and professes her love for Clark not Superman.
It was simply called Superman III
The end.
Attikus