3 answers
(click or scroll down)
The quote "The moment all the people were inside, total darkness ensued. Billions of consumer electronics started going offline" foreshadows a major event in the story where a widespread blackout occurs. This hints at a potential crisis that will affect the characters and plot significantly.
The author creates dramatic irony by having the reader know about the impending blackout before the characters in the story do. This builds tension and suspense as the readers anticipate the consequences of the blackout while the characters remain unaware. This discrepancy between what the reader knows and what the characters know adds depth to the story and creates a sense of anticipation.