Spike would ask 'who's there?' if this was a joke.

Drusilla giggles, but she's used to hearing the voices. "Hear that, my love? They call to us."

Knock, Knock

Those sounds again, deep underground - knocks echo down shafts like distant drums, muffled voices mutter wicked things over his shoulder…

…Go deeper… Lose yourself… Come closer… Don't hide…

"They call us to the Cornish tin. Want us to die in the mine. They don't know we're already dead," Drusilla whispers. "But it's iron we want. Blood and flesh and death."

Right now, Spike would settle for a stiff drink.