A/N: Alright, with so many crossovers like Trek!Lock and Who!Lock and Smaug!Lock, I couldn't help but take one and mash it with BBC's Jekyll (Also by the Moff, if anyone interested) and make this.
I don't own Sherlock, or Jekyll, or the Hobbit. All those go to PJ and the Beebs.
Molly Hooper tapped her Bluetooth impatiently in the dim light.
"You in? I got those specimens, now what do you need?"
The pathologist carried an armload of trays through the storage room of Saint Bart's, her pale features pinched in annoyance as she tapped her earpiece.
"Did you hear me?" The brown-haired woman demanded, a little louder as silence reigned on the other end. "I got those specimens, Sherlock, now what do I need?"
After a pause, the silence was broken by a voice that turned Molly's blood to ice. A slow, deep baritone, not unlike Sherlock's, but that rumbled with a rattlesnake-like hiss after each breath.
"Hello, Molly."
The specimens tray shattered on the floor, sending glass and various liquids everywhere.
"Oh, my stars, are you what Sherlock was talking about?" Molly squeaked, pulling the torch from her pocket and flicking it on. She swept it fearfully past the shelves, trying to see any sign of movement. The voice sounded again, each syllable enunciated in Sherlock's clipped accent.
"Sherlock's in bed now. Smaug is awake. And you're dead now."
Molly gripped the torch until her knuckles turned white, her legs becoming weak as adrenaline raced through her veins. She crept through the shelves, trying to get to the door but at the same time trying to spot any sign of an enemy.
"You turned off the lights, didn't you?" The voice inquired. "Foolish little Molly, foolish little dead girl!"
There was a clang from somewhere in the room, and Molly's heart just about leaped out of her throat. She whirled, scanning with the torch, but saw nothing.
"When the detective is out, I'm in." Smaug growled. "Oh, Molly, alone at last!"
"Smaug, you don't play these games, not with me!" Molly said, trying to keep her voice from trembling. "You've always had more sense!"
"Know what I've got now?" Came the rumbling reply. "You."
Molly whirled around, pulse kicking up as she heard the reptilian hissing coming from all around her. She ran to the fuse box, and tried to turn on the lights. Her blood ran cold when she saw what was missing from the metal box.
"I've also got the main fuse," Smaug told her in satisfaction. Molly ran to the door and tried to open it, but it wouldn't budge. She let out a cry of frustration and fear, spinning around to peer into the dim storage room. She dug into her pocket, trying to fine her keys, but they were missing.
"Yes, I took your keys." Smaug said smugly. Molly dug in her other pocket, but there was nothing.
"Yes, I took my keys, too." He went on. "Well, look at this, Molly. Everything you need for the perfect night in. A beautiful woman, a locked door, and no one around."
"You won't hurt me!" Molly exclaimed, scanning the dark shelves nervously, trying to keep her knees from buckling as icy fear coursed through her veins.
"I'll devour you!" Smaug roared, setting Molly's ear to ringing.
"You know the rules, if you hurt me, if you hurt anyone, he turns himself in!" Molly called.
"You turned off the lights!" Smaug reminded her.
"If anything happens to me, you think he won't know it was you?" Molly demanded, voice quivering, creeping through the shelves. "You think he won't guess?"
"You're guessing, too!" Smaug snarled.
"I know how he thinks!"
"I am how he thinks!"
"Then you've got a problem, because you like me!"
Molly felt a twinge of satisfaction at the silence on the other end of the Bluetooth, as though she had the monster truly stumped.
"Bet your life?" Smaug hissed in inquiry. There was a clatter, and Molly whirled to see her keys laying on the floor behind her. She turned again in case he was trying to creep up on her.
"Are you messing with me, Smaug?" She asked, unsure of what to do.
"Ten." Said Smaug, no longer from the Bluetooth.
"What?" Molly yelped.
"Nine."
"What is this, what are you doing?" Molly cried, looking all around.
"Eight. Seven."
"What are you doing?!" Molly shouted again.
"Six." The monster's voice was becoming increasingly more savage with each number. Molly raced towards the keys, unable to keep the cries of terror from escaping her.
"Five."
Molly snatched the keys, and ran for the door.
"No!" She cried, trying to get him to stop.
"Four."
Molly got to the door and fumbled frantically with the keys, her hands shaking so hard she dropped them.
"Three."
She scooped them up, and managed to jam the correct one into the slot.
"Two."
The door swung open, and Molly whirled around, gazing frantically into the dark room in search of Smaug. Then every hair on her neck stood on end, as she heard the rattlesnake breath close to her ear, and the gleeful snarl that set her mind on overdrive.
"Come to the King!"
Molly shrieked, spinning around and briefly catching a glimpse of her detective's curly hair, but his eyes were blazing gold with slit pupils, teeth bared in a psychopath grin. Molly stumbled away from him, tripped, caught herself, and fled into the forest of metal shelves. She heard rapid footsteps behind her, and a strong hand seized her shoulder, spinning her around and slamming her back against the nearest shelf.
"Don't run!" Smaug chided, amber eyes an inch from Molly's terrified brown ones. "Not from me. You know what runs? Food runs."
"If I tell you who I am, you won't kill me!" Molly whimpered, tears leaking from the corners of her eyes, her back digging painfully into the metal shelf edge. Smaug didn't loosen his steel-like grip.
"If I tell you who sent me, you won't hurt me. I know you won't." Molly said again. "Go on then, try me."
Smaug made a slight growling noise, then drew his head back a few inches.
"Catch you…later." He rumbled. Then he roared, baring his fangs a micrometer from Molly's face. She shrieked as his grip loosened, crumpling to the floor and burying her head in her knees. There was silence for a moment from the man, then he spoke. Molly's heart nearly broke with relief as she heard the familiar baritone, though he wasn't talking to her.
"Harm my pathologist again, and you and I are at war."
Then Sherlock sank to a crouch, wrapping his arms around Molly's heaving shoulders, one strong hand rubbing circles on her back as he comforted her, while inwardly vowing revenge on the monster within.