It contains the first appearance of the Black Mercy, a magical, extraterrestrial, plant-like organism which, upon symbiotically attaching itself to its victims, incapacitates them while causing them to hallucinate living out their greatest fantasy.
When the editor Dick Giordano finally approved the project that would become Watchmen, Moore and Gibbons began working on planning the stories.
[8] Batman, Robin, and Wonder Woman visit the Fortress of Solitude with gifts on Superman's birthday, February 29, but they find him catatonic, with an alien plant wrapped around his body.
The alien conqueror Mongul reveals himself, explaining that the plant – called the "Black Mercy" – has incapacitated Superman while it consumes his bio-aura, feeding him a realistic dream based on his heart's deepest desire.
In his catatonic state, Superman dreams of a normal life on his long-destroyed home planet of Krypton, happily married to Lyla Lerrol and with two children, Orna and Van-El.
Superman's fantasy takes a dark turn as his father Jor-El, whose prediction of Krypton's doom was unfulfilled, has become discredited and embittered.
Kryptonian society has undergone political upheaval, and the disgraced Jor-El has become chairman of an extremist movement "the Sword of Rao", calling for a return to Krypton's "noble and unspoiled" past through the establishment of a totalitarian theocracy under the leadership of Brother Lor-Em.
Kal-El decides to take his family away from the city for protection, only to witness Jor-El presiding over a political demonstration reminiscent of a Fascist rally, which dissolves into a riot between anti-Zone protesters and the Sword of Rao.
Lyla Lerrol, Kal-El's wife in Superman's fantasy, is renamed "Loana" and is an amalgam of both Lois Lane and Lana Lang, the two main loves of Clark Kent's life.
In the original comic story, Kal-El is depicted as the father of two children in Superman's fantasy, but in the animated adaptation, only the son, Van-El, makes an appearance.
Similar to Superman's experience, it becomes progressively more dark, with Joe slowly winning against his father, as Wonder Woman gradually frees Batman from the Black Mercy and he realizes the false nature of the fantasy.
The thirteenth episode of the first season of Supergirl TV series adapts "For the Man Who Has Everything", with the title changed to "For the Girl Who Has Everything", reflecting its being centered on Superman's cousin Kara Zor-El.
Unlike in the source material, the Black Mercy is depicted as virtual reality technology, and facilitates Brainiac's attempt to supplant Superman's consciousness and take over his body by trapping his mind in a fantasy version of Krypton.