I have a problem in understanding krushkal extension of Schwarzchild metric. So i solved the Einstein equation for the vacuum part of a spherically symmetric matter distribution and solved it in the inside region too. they are fine and compatible at schwarzchild radius. But the problem i am having is how come one is using the schwarzchild metric (solution of vacuum) and changing coordinates for few time and then finally in krushkal coordinates describing the spacetime all the way down to r=0 (but this metric solution we started with is a vacuum solution). How is this justified??? My second confusion is that what will happen if someone is close to horizon.. Does he feel sudden pull of infinite strength or is it very smooth as was elsewhere outside the mass.??? I think he should not feel any difference at least locally (as far as equivalence principle is concerned)..