Story: FANTASTIC FOUR#289 by John Byrne (writer and artist)
Synopsis: Basilisk crawls up from the construction area of the then future Four Freedoms Plaza. He brags about his return and starts declaring his plans. A construction worker shoots him out of the building and declares, "Justice is Served!"
Is the story key to the overall Scourge storyline? Borderline. John Byrne names Scourge for the first time here. Reportedly while Gruenwald came up with the character, Byrne came up with the name, and it suits the character well IMHO.
Does the scene tie into the main story in this issue? Not really, beyond tying into the subplot of the new headquarters being built.
Comments: Hammer and Anvil's death occurs chronologically after this one. However, the file is listed after Wraith's death since I'm going by publishing order first and chronological order second