"The Horror That Walks on Air!"
After thwarting an armed attack on the Baxter Building, the Fantastic Four are alerted to an Extraterrestrial threat: the arrival of Galactus' newest herald, Air-Walker! With the Silver Surfer's help, the team defeats Air-Walker, but then must once again face off against Galactus himself!
Reprints Fantastic Four (1961) #120-123.