“Ditto,” the kid says mildly. “Old dude.”

“You haven’t seen her either?” I ask hastily, trying to stave off a completely unmatched battle.

“Nope,” the kid replies. “But she’s disappeared before, like I told the boss man here. And his lackeys. And his lackeys’ lackeys. I hate it when she does this.”

I almost smile. He calls Ryodan’s men lackeys. I’d like him for that alone.

Unseelie begin sifting into the office since they can’t use the door. The room doesn’t hold many, considering how wide a berth they give all three males. Not just Ryodan and Barrons, who they always steer clear of by ten feet or more, but also the boy that must be Dancer if he’s heard Dani talk in her sleep. I grow more aggravated by the moment as they cozy up to my backside. Dancer? Really? They don’t bother a teenage kid?

Barrons and Ryodan are eyeing him, too, no doubt wondering the same thing.

Dancer shrugs. “Guess they don’t like my soap. They certainly like something about you. And dude, do they stink. So, what gives with this?” he asks me. “Why do they like you so much?”

“I find that fascinating myself,” Ryodan says. “Answer the kid.”

Barrons gives him a look. “Tell her what you just told us,” he says to Dancer.

Dancer pushes his glasses up on his nose, managing to look adorably brainy and hot in a collegiate hunk way. I get what Dani sees in him. He’s pretty much perfect for her. If only he had a few superhero parts. Dani is going to be hell on a man’s self-esteem when she grows up, and while Dancer doesn’t seem to suffer in that department, in this world caring about a mere human is a liability.

“After we defeated the Hoar Frost King, I couldn’t let it rest. Something was bothering me. I get obsessive like that when facts don’t gel, or do so in a way that seems to imply impending catastrophe. Then I have to—”

Ryodan says, “Not one fucking ounce of interest in your personal problems.”

“Christ, you’re a cranky bloke,” he says to Ryodan. To me, he says, “Each of the Unseelie has a favorite food. The Unseelie that was icing Dublin and its inhabitants was devouring a specific frequency.”

Okay, that’s weird. “Why would an Unseelie feed off a sound?”

“Dani and I speculate it was trying to complete itself. That it was aware it was derived from an imperfect Song of Making and was attempting to obtain the correct elements to evolve into something else.”

“Go on.”

“I was able to isolate the precise frequency: the flatted or diminished fifth.”

I had less than a month of music theory. “What’s the flatted fifth?”

Dancer says, “Mi contra fa est diabolus in musica—where the mi and fa don’t refer to the third and fourth notes of the musical scale but to the medieval principle of overlapping hexachords.”

I say impatiently, “Clarify.”

“Also known as Satan’s music, or the Devil’s tritone, it’s an interval spanning three whole tones, such as C up to F# or F# up to C, the inverted tritone. It’s used in sirens, can be found in the hymn ‘A Mighty Fortress Is Our God,’ Metallica’s ‘For Whom the Bell Tolls,’ ‘Purple Haze’ by Jimi Hendrix, ‘Black Sabbath’ by Black Sabbath, Wagner’s Götterdämmerung, the Dante Sonata by Liszt, Beethoven’s—”

“We get the picture. Get on with it,” Barrons growls.

“Mathematically speaking, harmonies are created by notes sounding together in proportion to one another that can be expressed in numbers. The Devil’s tritone is commonly assigned the ratio of 64/45 or 45/32, depending on the musical context … And your eyes are glazing and I haven’t even gotten started,” Dancer says. “Okay, then, it’s jarring, disconcerting, some even consider it depressing. There’s a lot of controversy about whether or not ecclesiastical sorts banned it in medieval times out of fear it could summon the devil, him—” He breaks off and grins at me. “—or herself. How’s that for laymen speak? Personally I find it challenging, invigorating—”

“Again with the we-don’t-give-a-fuck,” Ryodan says. “Tell her what you told us.”

The grin fades. “Like music, all matter is composed of frequencies. Where the Hoar Frost King took his ‘bites’ of melody from the world, it completely consumed that frequency.”

“What are you saying? We have no flatted fifths left?”