It was the final part of a four-part story of the Kryptonian Battle.
The world's military gives Superman just 48 hours to defeat Lord Nor, or they'll take on the "wacko Martian" themselves.
After surrendering, Clark is charged by Lord Nor for treason for not doing his destined duty, abandoning his people and committing adultery by marrying Lois (an Earth woman). He shows the Kryptonian council holograms and recordings as evidence. As a result, Clark is taken away to be disintegrated into matter and be scattered across the galaxy.
However, right afterwards, a messenger tells Nor that Metropolis refuses to surrender. In punishment, Nor vaporizes him with heat vision and orders Metropolis destroyed, thus revealing his true intentions and character to the council head, Lord Trey. At this point, Ching points out to Trey that Kal-El's sentence is illegal since he was never informed of his full rights; namely, the Right of Challenge, an ancient and obscure law allowing trial by combat for nobility. The desperate Trey throws his full weight to Kal-El's side. After communicating with Zara, Nor accepts the challenge.
Superman and Nor meet in Metropolis in front of the Daily Planet in an empty alley. Lois finds out that the corrupt Colonel Cash of the United States military has stolen a sample of Kryptonite from Star Labs and plans to use it as gas to kill Lord Nor while using the Man of Steel as bait which would kill him as well.
Lois goes outside to warn Superman about the gas as he overpowers Nor and wins the duel.
Afterwards Nor's men suddenly appear to fight Superman. The gas is fired, killing Nor and his men, but Superman survives due to being unconscious and the other Kryptonians absorbing most of the gas. Colonel Cash is then jailed.
Clark decides to stay on Earth and the Kryptonians leave for New Krypton with Zara as their ruler and Ching as her husband.
Later Clark and Lois decide that they should marry for real and this time not let anything stand in their way.