In Amazing Spider-Man #510, Peter receives a letter from his assailants in which they threaten to kill Mary Jane and Aunt May. Not wanting to alarm them, Peter remains silent about the content of the letter. Later, as Spider-Man, Peter pays a visit to Detective Lamont to get help in obtaining some latent handwriting impressions from Gwen's letter. After leaving Lamont, he calls his aunt to check on her. A male voice answers the phone and tells him that he has to make his way to a certain address in less than ten minutes or else Aunt May dies. Peter/Spider-Man web-slings as fast as he can and reaches the destination. As he approaches what appears to be Aunt May tied to a chair in the middle of the factory, his spider-sense goes ballistic and he realizes that it is a trap. He escapes a huge explosion that completely destroys the factory but he is partially caught in the blast. As he lies in the rubble of the factory, bruised and battered, the male assailant shows up and starts beating him to a bloody pulp. The intervention of the female assailant saves his life. The male assailant, however, vows to return and finish what he has started. Their names are revealed - the woman is named Sarah, the man Gabriel. Later that night, Peter/Spider-Man meets once again with Detective Lamont. The letter reveals that Gwen was pregnant when she left for Europe and that she had twins - their names: Gabriel and Sarah.

In Amazing Spider-Man #511, a distraught Peter tries to make sense of this shocking revelation. The scientist in him knows that it is impossible for Gabriel and Sarah to be Gwen's kids because if it were true, they would be children, not full-grown adult, such is the case here. As Spider-Man, he heads over to a Genetic Lab to perform some DNA testing using DNA left on the letter (by either Gabriel or Sarah) and DNA extracted from Gwen's grave during an earlier visit to the cemetery. While there, he is confronted, at gunpoint, by Sarah, who tells him that Gabriel doesn't want to just kill him but to make him suffer by killing everyone he loves. Sarah appears to hesitate when Peter asks her if she wants the same thing as her brother but she replies that the only way Peter can save the people he cares about is to willingly let her kill him right there, right now. Peter is literally saved by the bell of the DNA testing machine, which catches Sarah off-guard. Peter uses that opportunity to lunge himself at her and disarm her. He then pulls her mask off and is shocked to see that she looks exactly like her mother, Gwen Stacy. At that moment – almost on cue – a nearby window blows up, courtesy of a very impatient Gabriel, who had been waiting outside on a nearby rooftop. While Peter dives out of harm's way, Sarah storms out of the building and reunites with her brother, who immediately jumps to the conclusion that Peter's presence at the genetic lab confirms that he is their father and that he deserted their mother and later caused her death. Back in the lab, Peter checks on the DNA results, which confirm that Sarah and Gabriel are indeed the children of Gwen Stacy. Later, when Peter returns to his apartment, he finds a very distressed Mary Jane waiting for him. MJ tells him that she found the letter and read it. Peter replies that it can't be his kids because Gwen and him never slept together. MJ believes that Peter is telling the truth because she knows who the real father of Gwen Stacy's children is.

In Amazing Spider-Man #512, Mary Jane reveals to Peter that Norman Osborn is the father of Gwen’s children. It is also revealed that the twins are aging prematurely, as a result of the goblin formula coursing through their bloodstream, which they genetically inherited from their father. More information is introduced to tie some of the loose ends and plots holes of this farfetched story. For instance, the Green Goblin, Norman's alter ego, not only killed Gwen (on the Brooklyn Bridge back in Amazing Spider-Man #121) because she was Peter’s girlfriend but he killed her because she did not want him around her children; even though they were his as much as they were hers. As well, Peter realizes that the reason Osborn was after him to become his heir back in Amazing Spider-Man #25 (466) and Peter Parker Spider-Man #25 (123) was that he had brainwashed his kids into thinking that Peter was their father, therefore he was trying to coerce Peter into becoming part of his family so that he would take his rightful place as their father. Of course, that didn't work so Norman kept quiet about them. He did however continue to brainwash them into thinking that Peter had abandoned their mother and later caused her death, which is why they are so mad at Peter now. At issue's end, Peter realizes that he must try and save them because at the rate they are aging, they might die in a few years.

ACT 1: The story opens up with Mary Jane and Peter recollecting the events of the past few days:

(1) Getting a letter from the late Gwen Stacy in which she tells Peter that she was pregnant when she went to Europe back in Amazing Spider-Man #121;

(2) Finding out that she was impregnated by none other than Norman Osborn;

(3) Finding out that Norman Osborn led Gabriel and Sarah, the children born from their relationship, to believe that he, Peter, abandoned them and their mother and later killed her; and,

(4) Finding out that Gabriel and Sarah are aging prematurely at a very fast rate as a result of the Goblin formula coursing through their veins.

ACT 2: Later that day, atop the Brooklyn Bridge, Peter, as Spider-Man, waits for Gabriel and Sarah to show up. The media, which have been following the story as it developed, are also on the scene and their cameras are rolling. Finally, Gabriel and Sarah arrive, fully costumed and equipped with their weapons. Wasting no time, Peter tells them the truth and asks them to believe him. The truth, of course, is that Norman Osborn is their father and that he made them believe Peter was their enemy by feeding them lies and contorting stories. Succeeding into making them believe him however, is easier said than done. Gabriel, especially, is refusing to accept the truth and tells Peter how Norman raised them and how he made sure they always had the best of everything. He adds that Peter has to be their father since they have his strength. Peter goes on to explain to them that Norman was exposed to a formula that gave him tremendous strength and speed and healing abilities and that if that change was encoded into his DNA, then it is possible that it was passed on to them, causing their natural again process to speed up considerably. Gabriel replies that he does not trust Peter at all. Peter retorts that he may not trust him but that she does, pointing at Sarah. At that moment, Sarah takes her mask off and tries to convince Gabriel that Peter is telling the truth since she remembers that Peter tested their DNA only against Gwen's and not against his. She adds that he wouldn't have gone to all the trouble of getting DNA from Gwen's grave if he could simply use his own, meaning that he knew he couldn't be their father since he didn't slept with Gwen; so he didn't need to test his own (as seen in Amazing Spider-Man #511). Gabriel still does not believe Peter, saying that Norman was their anchor, their salvation. Peter replies that Norman was a murderer and that it was him who killed Gwen right where they're standing. Unable to accept the truth and furious at Peter for making allegations against Norman, Gabriel launches himself at Peter. Gabriel lashes out at Peter but Peter does not want to hurt him so he doesn't fight back and takes the punches. Sarah, in the mean time, yells at her brother to stop. Gabriel does not stop and ends up on top of Peter, strangling him. Suddenly, a gunshot is fired at both of them, missing Peter's head by a few inches. Gabriel lets go of Peter and looks down at the source of the gunshot. Down below, on the bridge deck, the police have arrived on the scene and are ordering them to surrender. Gabriel immediately suspects Peter of having brought along the police and goes into a fit. He takes his gun out and shoots at Peter. Peter dodges the bullet and pushes Gabriel off the bridge, knowing full well that he can survive the fall. He turns his attention to Sarah who is standing nearby. He is taken aback when he realizes that she's been accidentally shot by her own brother. Everything seems to go into slow motion from that moment. Sarah faints and falls off the bridge (she was standing next to the edge of the top of the bridge when she was shot). Reliving the worst day of his life, Peter jumps in after her, swearing that he will not let it happen again. As her limp body falls towards the icy Hudson River, Peter catches up to her and saves her life, sans the neck breaking, which caused her own mother to die. He then web-slings away, leaving the police and the media behind. Down below, Gabriel emerges from the river and yells Sarah's name out.

ACT 3: Peter brings Sarah to the hospital to get her immediate medical attention. Meanwhile, Gabriel is making his way through the sewer system to a location he remembers, having somehow memorized the instructions on how to get there. He also remembers always wanting to go there with his sister after they avenged their mother and killed the man who took her life. After a long walk through the sewers, he finally comes to a dead stop in front of a large metal door. He opens the door and steps in. He is shocked and appalled when he sees what stands in front of him: two large containment units containing two Green Goblin costumes, a green and purple one intended for Sarah and a blue and grey one intended for him. To be concluded.