The Ultimate Vampire Resource and Directory

Dr. Leo Quintum and his P.R.O.J.E.C.T. Team are exploring the Sun when they are sabotaged by a booby-trapped, genetically enhanced Lex Luthor clone. Superman saves the day, but it turns out that his body has been overdosed with solar radiation that not only gives him new powers but now is slowly killing him. Luthor, having orchestrated the death of Superman while under the employment of General Sam Lane, is arrested thanks to Clark Kent's article and sentenced to death.

Deciding to keep his impending death a secret from the public, Superman reveals his secret identity to Lois Lane because he wants to spend his remaining time with her. Though Lois was unable to accept it after years of him keeping the truth of his identity as Clark Kent from her, Superman takes her to the Fortress of Solitude. During this visit, Superman's secretive behavior and indirect exposure to alien chemicals heightens Lois' paranoia to the point of attacking Superman with a kryptonite laser. However, seeing the solar radiation has now made him immune to green kryptonite, Superman is able to calm her down and reveals that his secret was that he has been preparing her birthday present: superpowers for 24 hours.