An [[exorcism]] will cause a demon to leave its [[meatsuit]] and returns to Hell, whereas the [[Colt]] and [[Ruby's Knife]] can kill a [[demon]], either destroying it permanently . With his psychic abilities Sam exorcises, and eventually is able to kill demons.
[[Castiel]] reports that angels laid siege to Hell to rescue Dean before he broke the first seal, but did not reach him in time. Eventually, it is Castiel who rescues him. Castiel also says that [[Lucifer'
s Cage]] is too well-guarded for even angels to acccess <sup>6.07 Family Matters</sup>