Juliette Binoche/Sandra Brody aka Bryan Cranston's wife and Aaron Taylors Johnson's mother is shown to be trapped in a contamination room in the trailers of the movie...

the official synopsis writes "An epic rebirth to Toho’s iconic Godzilla, this spectacular adventure pits the world’s most famous monster against malevolent creatures who, bolstered by humanity’s scientific arrogance, threaten our very existence."

bolstered by humanity’s scientific arrogance was bolded because it specified that the other creatures in the movie was created by humans themselves

so... a potential plot twist could be that Juliette Binoche/Sandra Brody is seen in a contamination room possibly because she herself is turning into a monstrous creature supposedly caused by radiation.. she could possibly turning into 'another spoiler':





Binoche and Cranston's reportedly signed on after the reading of one scene in the movie... this could be it

Another possibility is Binoche turning into Godzilla herself causing her to have a connection with the main character which is her son... but this is less likely to happen because it was shown that Godzilla travelled from Japan to USA in the movie...

Anyway... if Binoche does transforms to any kind of creature... the effect will be the combination of drama, gore fest and social critic of human society.