"I didn't think there was," Gabriel said miserably, meeting Valkyrie gaze because he had to, but not liking the accusation he saw in it. "Rafe doesn't have the skill in music and spoken word. That's why he brought Merlin. And since Merlin is bound to the same metaphysical laws as any mortal, they had to have opened a portal on Earth, where Lucifer would be able to find it. I confess that possibility didn't occur to me. I'm sorry."

He bit his lip again and looked away, into the wall--through the wall. And this must surely be another reason why they weren't to reveal themselves to mortals. The questions. The expectation. "It's not that easy. Lucifer has the right to his own choices just as much as anyone else. My Master can't simply interfere by making him go away. Even their wagers have always relied upon humanity to reject or accept Lucifer of their own will."