This is a well written novelization of the 2006 movie of the same name. Like the movie it is a virtual sequel to Christopher Reeve Superman II movie.
Clark/Superman/Kal El has spent years traveling to the location of Krypton, after astronomers on Earth announced that they had found the supposedly lost planet and it showed signs of life. But when he arrives there is nothing left but a burnt out fragment.
Returning to Earth after 5 years, he finds that the world has moved on, learning to survive without him. And so has Lois Lane, who is now engaged to Perry White's nephew and has a son.
Furthermore Lex Luthor has gotten out of jail and is again trying to realize his dream of world domination. What's more he has raided the Fortress of Solitude and is using Krytonian technology to do it.
So Superman faces a challenge that even he may not be equal to, while trying to find a place in the world again and dealing with a wounded heart.
Those who saw the movie will find much of the story familiar, but the novel has more space to deal with the emotional issues, and there are some significant differences.