Who is "The Escapist" in the novel, The Amazing Adventures of Kavalier & Clay?

The Escapist is a superhero, who has the ability to help others escape from oppression and captivity. In the comic-book story, he is really Tom Mayflower, who is given a Golden Key from a dying man who adopted him, Max Mayflower. The Escapist character is accused in the courts of being a copy of the character, Superman.