He had one chance to show the world he was still the King of Rock 'n' Roll. Discover the story behind Elvis Presley's triumphant '68 comeback special.He had one chance to show the world he was still the King of Rock 'n' Roll. Discover the story behind Elvis Presley's triumphant '68 comeback special.He had one chance to show the world he was still the King of Rock 'n' Roll. Discover the story behind Elvis Presley's triumphant '68 comeback special.