20 Things You Somehow Missed In Shutter Island
1. The Sun Only Comes Out At The End
A major component of the film's atmosphere is the increasingly chaotic weather throughout Teddy's journey.
When he "arrives" on Shutter Island, the sky is dull and overcast, and over the course of the first half the weather becomes increasingly dire until a full-on storm breaks out.
Even once the storm passes, almost the entire remainder of the movie has a grim pallor to it, until once Teddy's delusion has finally been broken at the end, we eventually see that it's now a sunny day.
The visual metaphor speaks for itself, of sun breaking through the storm, even as the ending implies that Teddy feigns a relapse in order to be lobotomised and forget that he killed his wife after she drowned their children.