The infected start making their way back up the building. George causes a leak in the gas pipes that kills all the infected except Sally in an explosion. Hannah and George search for a way out and go into Sally's apartment, finding the two hidden partygoers. The group make their way to the roof but are stopped by Sally. She infects the two partygoers, but George dispatches them. George and Hannah lower themselves to the roof of an adjacent building, fighting Sally as they go. Inside the neighboring building, Hannah gives birth to the couple's child. George defeats the resilient Sally in mortal combat, and he and Hannah exit with their newborn child.