Avengers (1963 1st Series) #233

The Annihilation Gambit!" Plot by Roger Stern and John Byrne. Script by Roger Stern. Art by John Byrne (breakdowns) and Joe Sinnott (finishes). Cover by John Byrne and Joe Sinnott. 

A strange and powerful force field is emanating from the Baxter Building and spreading outward across Manhattan! Who has created this massive barrier? The lord of the Negative Zone!