What is the plot of 'El Eternauta' comic book?

'El Eternauta' tells the story of a man who is exposed to a mysterious, unknown radiation on a military base in Buenos Aires. This exposure causes him to evolve into a superhuman being, a 'Eternauta' (eternal sailor), who becomes a symbol of resistance against a looming, unspecified threat. The story is a metaphorical exploration of the Cold War, existentialism, and humanity's relationship with technology and the unknown.