Fili knew. Of course he did. Known for months. Maybe the whole time? Heh. Wouldn't put it past him. Keener eyes there never were. Not that Kili opened up about it. How long since it happened? Six months? Two years? Already an eternity. Hard to tell time with thirst searing every thought. But Fili never mentioned it. Ever.

Not when he stumbled over Kili at four in the morning. Sprawled on the front stoop, blood everywhere. Not a word as he hauled him to the tub and stained the porcelain, bloody water up to his elbows. Kili drunkenly crooned wistful ballads, eyes glazed with hazy satisfaction and not a whiff of alcohol on his breath. Only the sharp scent of metal.

Not when Kili was starving. Limbs shaking, fangs dropping, pupils blown, bone splintering grip on Fili's wrist while walking through public spaces. Brows pinched, eyes drawn to that tantalizing artery leisurely pulsing above Fili's collarbone.

"Camping," Fili would suggest. And not a stir from his cot that evening as Kili slipped from the tent, not even bothering to zip the flap back in his haste. Not a second glance the next morning at abnormally red lips.

Time granted control. Overpowering thirst lessened to throbbing ache. Manageable some days, not so much others. Desperate need lifted as a fog. He saw more than meals. Heard more than heartbeats. Smelled more than sweet metal. Instead he smelled...a difference. Something distinctly canine.

"Did we get a dog?"

Fili frowned. Shook his head. "You're losing it, bro."

Maybe, but Kili couldn't unsmell it. Weeks passed. Fili didn't come home one night. Kili waited, he's never tired anyhow. Morning returned. Fili didn't. Early afternoon, Fili walked in. Sweat clothes. Duffel bag. Haggard as hell. Mulish. Wouldn't acknowledge Kili's attempts at conversation.

Next morning, he's his usual self.

"You alright?" Kili asked.

"Same as always. Why?"

Kili frowned. Shrugged.

Next month it's the same.

And the next.

And the one after that.

Next time Kili followed. The new hunger came with other perks. Some eerie, some useful. Like walking without making a sound. Not needing to breathe helped too. Fili took a lot of turns. Ducked down several back alleyways and side streets Kili never considered wandering down before it. Kili found himself in a dead end. Had he missed something? Blinked. Sniffed. No, Fili definitely turned here. So where?

Sour and rotting unmentionables burned his sensitive nose. He looked down. A man hole beckoned in a dumpster's shadow. Kili descended rusty rungs, trailing Fili's strengthening scent through a maze of sewer works ending outside a locked door.

DO NOT ENTER

AUTHORIZED PERSONEL ONLY

Kili frowned at the graffitied warning. A small slot covered by a grate gave him a limited view of the dim room opposite. Fili crouched in a shadowed corner, face twisted in pain, mouth open in silent torment. His body convulsed and shuddered. Snapping and cracking of breaking bone filled the air. Kili gaped at his poor brother as he writhed and fought the transformation. Inhuman wails and screeching echoed through the tunnels, dying before they ever reached the surface. But Kili heard them. Back to wall, he slid down, fist crushed to lips. When silence returned, Kili crept up, morbid curiosity getting the better of him. Inches away, a pair of yellow eyes met his through the grate. If Kili had been alive, his heart would have stopped right there. The beast roared a challenge, salivating and pummeling the door. Determined to tear him apart.

"Well this complicates things," he whispered.