Superman learns Lex Luthor is dying, and he wants the Man of Steel to help him find the cure for whatever is causing his rapid decline.

While the world wants to say good riddance to Luthor, Superman will go to the ends of the universe, through different dimensions, and across time to save his foe.

But just why does he want to save the person who's spent his life trying to destroy him? And will he even be able to find the solution?