The story
From a scene in the film Indiana Jones and the Kingdom of the Crystal Skull (2008), where the main character survives a nuclear detonation by hiding in a lead-lined refrigerator.
Etymology from Wiktionary, CC BY-SA 4.0.
nuke the fridge
Today it means: To suddenly include a strange or illogical event, often leading to radical and often disappointing changes to the narrative of the film. Full definition →