Plot Summary

After his last defeat at the hands of Spider-Man, the Green Goblin plans to make his foe as the heir to his "legacy" by slowly brainwashing Peter and having him go on a sleepwalking rampage as the Green Goblin. Eventually, Osborn kidnaps Peter and brings him to an old estate of his where he attempts to have Peter embrace the darkness as Osborn once did and become the next Goblin. After going through many tortures, Peter becomes mentally fragile and was about to drink a Goblin serum presented to him by Osborn but manages to overcome his foe's mind games and despite being weakened, defeats the Goblin but in the process, Peter is forced to accept the fact that him and Norman are alike and the villain vows before escaping that the next time they meet, one of them will die.  

Full Plot

At the end of the Final Chapter story arc, Norman Osborn insanity had further succumbed to insanity due to the Gathering of Five ritual and after he was defeated by Spider-Man and taken to a hospital, a group of Scriers led by Norman's friend Donald Menken saved him and helped him regain his sanity privately. However, while in the care of Scriers, Norman has become dependent on drugs made for him by his private physician Dr. Albert Bendix to maintain his sanity. Menken has also sought the help of a beautiful Swedish nurse named Kolina Frederickson whom Norman would eventually fall in love with because she reminded him of his first true love Emily Osborn. Despite his romance with Kolina, Norman continues plotting against Spider-Man and now that Peter is vulnerable due to the apparent death of Mary Jane, Norman sees this as the perfect time to strike.  
Norman exposes Peter to a gas that blocks his spider-sense and while disguised as a mailman, gives Peter a toothpaste containing hallucinogen and specially designed RNA compounds which Norman plans on using to manipulate Peter.  
  
Norman disbands the Scriers and in their place forms the Order of the Goblin and proclaims himself as the Goblin King. He then throws the body of a person wearing a Spider-Man to his loyal followers who viciously kill him following Norman's order. The man under the costume is revealed to be Dr. Bendix. At his Estate, Norman opens up to Kolina and tells her about the building and the loss of the Osborn family fortune and after Kolina shows her care and support for his efforts in reclaiming his fortune, Norman is reminded more of Emily and his love for Kolina continues to grow. 

Meanwhile, Peter has been suffering from intense Goblin-related dreams and delusions but is still unaware of Norman's plot. While visiting Aunt May, Peter is given by his aunt a music CD that was sent to her by a friend of Uncle Ben's and asks Peter to copy the music onto a tape for her. However, the CD was actually sent by Norman and it contains subliminal messages aimed at bending Peter to Osborn's will. When Peter listens to the CD, he starts suffering from more delusions 
 

One night, while searching for Norman, Kolina accidentally stumbles upon Norman's secret lair where Norman was there, wearing his new Goblin Lord costume. Startled by Kolina's intrusion, Norman hurled by instincts a Pumpkin Bomb at her, almost killing her. Norman regretted his action and after seeing Emily in Kolina yet again, decides to tell the nurse about his Goblin-side Kolina tells Norman that the Goblin serum ruined his life but Norman objects that the serum made his life better. Kolina tells Norman that he has lost his mind, provoking him into lashing out at her following Menken's suggestion to kill because she knows too much but  her resemblance to Emily stop him from hurting her. Menken pulls out a gun and attempts to finish her himself but this enrages Osborn who viciously attacks Menken and would have killed him had it not for Kolina's interference. After taking his medicine and calming down, Norman orders his servants to take both Kolina and Menken to his Adirondack Estate.  
 
Peter has a dream that involves the Green Goblin holding the deceased body of Spider-Man and throwing into the waters below the Brooklyn Bridge. The Goblin then unmasks to reveal Peter underneath. Then on, the body of Dr. Bendix, dressed in a Spider-Man is found by the police who are convinced that this is not the real Spider-Man and report that the Green Goblin was seen disposing of the body. Peter realizes that the murder and the dream are somehow related. After having another nightmare, Peter is informed by his friends Randy Robertson and Glory Grant that the Green Goblin has attacked them so he goes to investigate but becomes increasingly worried when he is unable to find him. Peter goes to Aunt May's house where he sleeps and after going through another horrible dream, discovers that the Stacys' house is burning. After saving Paul Stacy from the fire, he is informed that the Goblin was also responsible for this and he is angered by the fact that the Goblin attacked while he was asleep. After brushing his teeth at home, Peter realizes that his toothpaste is drugged and collapses immediately thereafter. 
 

Peter wakes up in Osborn's mansion where he greeted by Osborn himself who tells Peter about his experience with the "darkness" as a child and how it saved him. As a child, Norman's abusive father, Amberson Osborn,  locked Norman alone in one of the family's dark empty houses  in order to cure his son's fear of the dark. While he was alone in the house,  Norman encountered and feared a "green goblin-like" monster stalking him. Alone in the dark, Norman feared the monster would eat him once the darkness is replaced by the light, so he came to grip with the darkness, wishing it would never leave him. That night, he realised that the Darkness is better than the light.  Encounters like these made Norman develop a need for power and wealth so he would not become a failure like his father. He sought to regain the wealth he once had and he would stop at nothing to reach his goal. Norman wants Peter to have the same experiences and tries to coerce Peter into "embracing" the darkness as Norman did in the past, all in an effort to make Peter the heir to his Goblin Legacy.  Norman tells Peter that he realized Peter was the rightful heir when he saw Peter secretly visiting the hospital during Normie Osborn's birth in the story. After putting Peter through many tortures, Peter's spirit seems to have been finally broken, as he is evading the light and heading for the darkness. Norman presents Peter with a Goblin Formula and before a mentally fragile Peter could drink the serum, he sees an image of Aunt May telling him how much of a good boy he's always been. Peter throws the glass in the Goblin's face and the two foes fight. Despite being mentally and physically weak, Peter finally manages to defeat the Goblin. However, before escaping on his Glider, Norman proclaims that he has won because Peter chose the darkness over the light. The Goblin tells Peter that they are both alike and promises Peter that the next time they meet, one of them will die.