I've just watched Return of the Jedi. I've seen it many times before, but despite this, something struck me which I'd never really thought of before.
Why does Darth Vader die???
Just to remind you, here's what happens. Luke and Darth are having a good old light sabre battle and Luke unleashes his anger and starts smashing away at Darth on a bridge. Luke gets a good, strong shot in and hacks off Darth's right arm at the elbow. A good shot and pretty disabling from the heavy-breathing one's point of view. However, considering Luke's had his own arm chopped off and replaced twice, and that Darth originally lost all four limbs in a pool of volcanic lava, you wouldn't think the loss of an arm would cause him to stop living.
Anyway, then Luke throws his light sabre away and tells the Emperor that he won't turn to the dark side. The Emperor unleashes a can of whoop-ass in the form of some blue lightening bolts and Luke screams in agony.
Darth gets up and is apparently in colflict over what to do - but at this point, despite his limb-loss, he's essentially healthy - breathing and moving normally. Eventually, his good side overcomes his bad one, and Darth picks up the Emperor and chucks him down a hole.
Suddenly, Darth is dying. He's having difficulty with his infamous breathing and can't walk too well. Luke has to half carry him to his ship to escape. Then Darth requests that Luke remove his mask. Luke points out that he'll die if he does. Darth says, "Nothing can stop that now." His mask is removed, they have a tender moment and Darth carks it.
So my question remains - why did he die? Losing an arm was never a problem for Star Wars characters before. Anyway, he still had the strength to chuck his master down a hole. But all of a sudden he's on the way out!
Can anyone explain where the life threatening injuries which suddenly killed Darth Vader actually came from?