"Nuking the
fridge" refers to the moment in a film series when it becomes apparent that a certain installment is not as good as previous installments, due to ridiculous or low quality storylines, events, or characters.
Originating from the film "Indiana Jones and the Kingdom of the Crystal Skull," Harrison
Ford's character survives a nuclear detonation by getting into a lead-lined
fridge before being
blown thousands of
feet only to
crash back down and emerge safely.
The absurdity in this occurrence is that, although lead is radiation proof, lead melts at 620°F and is not resistant to the millions of degrees, that
say, an atomic
bomb would put out. This is the prime example of the lower quality and outlandishness disgorged as a continuation of the series, and thus the phrase was coined.
The saying is also a reference to the phrase "jump the shark," referring to an episode of Happy Days where the Fonz jumped a shark on water skis, considered the lowest point of the show. "Jumping the shark" is applied to a television series alternatively to film.
"Star Wars really nuked the
fridge when Jar Jar Binks was introduced."
"Indiana Jones 4 nuked the
fridge when they nuked the
fridge."