Eve

Dragons are abducting young women (virgins) and keeping them captive in a sewer. Dean obtains the Sword of Brunswick and he and Sam track down the dragon's lair, finding a pile of gold, and the women. They also find an ancient manuscript which speaks of freeing Mother from Purgatory. Sam and Dean kill one of the Dragons but one escapes. He meets up with another dragon who has also captured a half dozen women. They take one and use an incantation to open a door to Purgatory. They throw the woman in, and she rises again giving form to Mother.