There are few places creepier than a deserted computer lab in the middle of the night. And believe me, I know creepy.

Dozens of fans whirred, their white noise pressing like cotton into my ears and making me jumpy about what I wasn’t hearing. Eerie blue light half-lit the room; other lights blinked randomly on the machines. Although it was late January, fans blew in streams of frigid air. Even with my leather jacket over my sweater, I had goose bumps prickling both arms. I was alone with MIT’s new supercomputer, and that made this particular deserted computer lab supercreepy.

That, and the fact that I wasn’t really alone. In here with me, somewhere, was a demon.

That’s why I’d been called in, to exterminate a Glitch in the supercomputer. Supposedly the world’s third biggest, fastest, and smartest, lately this giant machine hadn’t done anything but spit out error messages. The MIT brainiacs tried everything they could think of to eliminate the Glitch, but none of their usual fixes worked. In desperation, they called me. I’m Victory Vaughn, Boston’s only professional demon exterminator. And I deal with Glitches the old-fashioned way: by killing them.

Fifty or sixty locker-sized cabinets, each holding multiple processors, lined up in rows like ghostly soldiers standing eternally at attention. I opened a cabinet, leaned in, and sniffed, checking for that characteristic Glitch smell: a strong scent of ozone with an undertone of grape bubble gum mixed with sardine paste and rotten eggs.

Nothing. I’d been here half an hour with no luck. It was slow going. A supercomputer is basically a series of ultra- fast processors linked together to ramp up the computing power. All those processors in all those cabinets gave the Glitch hundreds of places to hole up in our little game of hide-and-seek. I opened the next door. Come out, come out, wherever you are. Inside, a tangle of wires and cables snaked around stacks of circuit boards. Hard to believe a mess like that could perform billions of calculations at the speed of light. Except it couldn’t—not with the Glitch frying its circuits. I sniffed again, then tensed at the sharp smell of ozone. Beneath it, almost too faint to detect, was the stomach-churning odor of Glitch.

I pulled my rubber-lined electrician’s gloves from my belt and put them on. Clumsy, but a necessary precaution. A Glitch can take two forms. When the demon invades a machine, it’s pure magical energy that feeds off the electricity passing through its host. Outside its electronic nest, a Glitch has a physical body the size of a large teddy bear—but there’s nothing cuddly about its slimy purple skin, needle-sharp teeth, and inch-long claws. A shimmer of energy buzzes over its skin; touching one is like sticking your finger in an electric socket. That’s what the gloves were for.

To draw the Glitch out of the computer, I needed to force it into its physical form. So I’d brought Glitch Gone, an anti-static spray that won’t hurt the machine but forces the Glitch out. When that happens, the Glitch stays stuck in its physical form for a minute, maybe two, before it can turn back into energy and re-infest a machine.

I sprayed a light mist of Glitch Gone inside the cabinet, moving the can back and forth to make sure I didn’t miss a spot. Stepping back, I readied my bronze-headed ax, gripping it as best I could in the electrician’s gloves. With any luck, I’d split the Glitch in two before it attacked me.

Inside the cabinet, the processor lights began to blink faster. A spark shot out, then another. The Glitch stink intensified. Sparks, coming faster now, swirled into a pinwheel. The wheel spun faster, coalescing into a solid blur of light. I squinted against the brightness, trying to focus on the shape the light was taking. Then energy blasted out, a screech sliced the air, and the Glitch sprang.

I jumped back and to the left, but claws swiped my cheek. With the slash of pain came a teeth-clenching electric shock that almost knocked me off my feet. I staggered, and the Glitch leapt at me again. This time, I brought down the ax with both hands, but the damn demon was too fast. It sped away, and the ax buried itself in the floor.

I tugged at the handle, turning my head left and right to see where the demon had gone. It was too soon for it to reenter the computer—I hoped. My Glitch Gone spray was a couple of weeks past its expiration date. As the ax started to give, a yowl sounded behind me and the Glitch landed on my back. I staggered. The demon couldn’t shock me through my leather jacket, but what I heard promised something worse. The Glitch was hawking up a big wad of spit.

Glitch saliva is both disgusting and dangerous. It’s purple, has that grape-and-sardine smell, and it’s where the phrase “gumming up the works” comes from. Worse, the stuff is venomous, gradually penetrating skin to deliver its poison. A couple of days of hard, repeated scrubbing gets rid of it, but I was not going to spend the next week washing Glitch spit out of my hair.

I reached back, yanked the Glitch off me, and slammed it onto the floor. I got both hands around the ax handle and swung. Missed by a hair. The Glitch zipped out from under the blade and leapt on top of a cabinet. It started hawking again, its yellow eyes squinting, its body bobbing with effort. At the same time, the sparks that sizzled over its skin began to consolidate and swirl into a circle above its head. Damn it, the Glitch Gone was wearing off. If the demon jumped back into the supercomputer now, it’d double the amount of damage it had already caused. I swung, but again the Glitch jumped clear. The cabinet didn’t, though. My ax slammed through its top and into the processor inside.

Oops.

No time to worry about collateral damage. I spun in the direction the Glitch had gone, in time to see a stream of sparks flow into a video camera mounted in a corner of the room.

“Oh, no, you don’t!” I grabbed my Glitch Gone and raced to the camera, which I blasted with a big cloud of spray.

Sparks shot out like fireworks. I ducked as the camera exploded. This time, the Glitch materialized almost immediately. It hurtled at me feet first, knocking me backward with its powerful legs, using my chest as a launchpad to rocket off in the opposite direction. Damn, that hurt. The Glitch sped down the aisle between two rows of cabinets, toward the back of the room.

I took off after it, clutching the ax with both hands, my boots pounding the floor. I skidded around the corner where I’d seen it turn. The Glitch launched itself at me, claws aiming for my eyes. I dodged and swung. The ax smashed deep into the side of a processor cabinet and, again, got stuck. Instead of giving the Glitch another chance to attack, I whirled around, reaching for the throwing knife in my ankle sheath. The Glitch jumped at my face, but it overshot and bounced off the wall. It landed with an oof and lay on the floor. I threw. The damn Glitch rolled, and my knife barely scratched its arm.

The demon emitted a nails-on-chalkboard screech and clambered to its feet. It took off down the next aisle, running toward the front of the lab. It was fast, but not with its previous speed. I glanced at the ax embedded in the cabinet, then retrieved my throwing knife instead. Its bronze blade showed spots of purplish-black blood. Good. Bronze is lethal to demons, and even though I hadn’t wounded the Glitch deeply enough to kill it, the touch of bronze had slowed it down. Even better, the scratch from the bronze blade would prevent the thing from shifting into energy. That Glitch was mine.

I wiped the blade on my jacket sleeve and crept down the aisle, pausing every few feet to listen, but I couldn’t hear anything through the whirring of all those fans. I scanned the tops of cabinets towering on either side, my arm aching with tension, ready to throw the knife at the first sign of a purple blur speeding toward my head. Next time, I wouldn’t miss.

At the end of the aisle I wondered: which way—left or right? I held my breath, straining to hear through the white noise. My ear caught something. I listened harder. There it was again, a shuffling to the right. I eased off the electrician’s glove—no way I was going to let the clumsy thing mess up my aim this time—flexed my fingers, and got a good grip on the knife. I drew back my arm, ready to throw, then whipped around the corner.

And found myself face to face with the barrel of a gun.

“Don’t shoot!” I dropped the knife and showed my open, empty hands.

The face behind the gun came into focus: a wide-eyed fiftyish guy in a campus police uniform. His gun shook.

“I’m not armed,” I said, standing absolutely still. A shaking gun means a jumpy trigger finger. “I’m authorized to be here. Check with Professor Milsap.”

“You hear that, Professor?” the cop said over his shoulder. “Says she’s working for you.”

Milsap was here? Good. He’d clear this up, and then I’d finish the job.

“Professor Milsap,” I called out. “It’s Vicky Vaughn. Please tell the officer to put down his gun.”

“I will in a moment,” said a deep voice. Milsap appeared behind the still-shaky cop. He was tall and thin, with a full head of wavy gray hair—kind of Einstein-esque. He glared at me through wire-rimmed glasses. “As soon as he’s arrested you for vandalism.”

The rest of me wasn’t moving, but my jaw dropped far enough to hit the floor. “What are you talking about? You hired me to do this job.”

“We saw what you did. I arrived at Officer Hadley’s station in time to see you disable the surveillance cameras.”

“I didn’t—”

“You sprayed an aerosol can at a camera, and then the system went down.”

“That wasn’t me, that was the Glitch—”

“And now we arrive on the scene to find you’ve taken an ax to several processors.”

“Trying to kill the Glitch you hired me to exterminate.” My voice squeaked with indignation. I hate when that happens. “I warned there could be damage to the facility. There’s a clause about it in the contract you signed.”

“What contract? I signed no contract.”

“He’s lying!” shouted an indignant female voice. A second later, a teenage zombie in a Hello Kitty T-shirt stomped around the corner in her size-eight, pink, sparkly platform sandals. Tina, my self-proclaimed apprentice, scowled like she’d been grounded two days before the prom. This would be the same self-proclaimed apprentice who was supposed to keep track of my paperwork.

“He tricked me, Vicky! He said he wanted to check something in the contract, so I gave it to him. He stuck it in his pocket and ran out. He locked me in his office.” She glared at him. “You need a new door, asshole.”

“Tina! You can’t talk to a client that way.” Not even if he was proving to be a certified, grade-A, world-class asshole. I was kind of glad she’d used her zombie strength to demolish his door.

“But he—”

“We’ll talk about it later.” First, I’d figure out how to make the campus cop quit pointing his gun at me.

Milsap patted his pocket, half-smiling, and then frowned at me like I was a disappointing student who’d failed an exam. “Do you honestly think any reasonable person would believe MIT hired an ax-wielding maniac to deal with a simple computer glitch?”

“But I didn’t,” I said.

The pursed lips twitched downward into a frown. “Didn’t what?”

“Deal with it. The Glitch is still loose in here somewhere.”

“Oh, come now. We both know there’s no such—”

Tina screamed.

The cop’s eyes bugged out, and he fired.

I dropped, but the shot slanted upward; he was aiming at the top of the cabinet, not me. As he squeezed the trigger a second time, a glob of purple goop sealed the pistol’s barrel. The gun blew up in his hand. He fell over sideways and lay still.

Above me, the Glitch was noisily hawking up another wad of spit. I scrambled to my feet, feeling around for my knife and yelling, “Take cover!”

Tina disappeared down an aisle, but Milsap stood and stared at me. A second later—ptoooie!—Glitch spit splatted on the side of his head. Looking dazed, he put his hand in the mess, trying to brush it off but managing to smear it around and get it all over his hand.

“Don’t,” I said. “It’s poison.”

He stared at his hand in disbelief.

From nowhere, the Glitch landed on Milsap’s shoulders, clawing at his face and spitting in his hair again. Milsap screamed and went down. The Glitch jumped away but was immediately back on top of the guy, sitting on his chest, gripping his throat with its claws, and crackling with electricity. Milsap’s cloth blazer didn’t offer any protection against the Glitch’s energy field; he howled and shook like he’d grabbed a live wire.

It was more like a live wire had grabbed him.

Time to finish this job. I kicked the Glitch, hard, and threw my knife. The Glitch flew across the room and hit the wall by the door. My knife flew with it. The blade struck the Glitch dead center, pinning it to the wall. The bronze did its thing, and the Glitch disappeared in a puff of evil- smelling smoke. All that remained was a slimy purple stain on the wall.

I went to the cop first, pressing my fingers into his neck to check for a pulse. At my touch, his eyes fluttered open and he struggled to sit up. “What the hell—?” he muttered, staring at his hand. He had a nasty burn, but he’d be okay and I told him so.

Milsap was another matter. He lay on his back, moaning, his face and neck striped with multiple slashes. Thick, sticky Glitch spit matted his hair and coated his glasses. The whole right side of his face was purple with it, and it had gotten into his wounds.

Good thing, too, I thought, as I heard Tina clomp-clomp back down the aisle. Zombies have this little problem with human blood—the smell of it sends them into a frenzy of hunger. Glitch spit gummed up Milsap’s wounds, and the stench of it covered any scent of blood. Tina wouldn’t try to gnaw his face off. On the other hand, it was a bad thing, because the venom in the Glitch saliva, normally slow-acting, would work faster where the skin was broken.

Tina appeared. She stood over Milsap, hands on her hips. “No such thing, huh?” Her voice oozed with sarcasm. “Asshole.”

This time, I didn’t rebuke her. Instead, I told her to help me get Milsap on his feet. I grabbed his right arm; Tina took his left. At the count of three, we heaved.

“Where’s a bathroom?” I asked Milsap when we’d gotten him more or less upright. “We need to wash out those scratches before the poison takes effect.”

Tina and I each managed to drape one of Milsap’s arms around our shoulders. Then we guided him across the room. Except he couldn’t seem to keep his feet under him, so there was a lot more dragging than guiding. In the hallway, he looked around like he’d never been there before. His spit-coated glasses sat crooked on his face, obscuring his vision. I plucked them off, and he blinked.

“Bathroom?” I reminded him.

He tilted his head left, so we went that way. Ten yards down the hallway was a door marked Men. We half-walked, half-dragged Milsap to it. I shouldered it open.

The room smelled of disinfectant with an undertone of old mildew. We got Milsap across the scuffed tile floor to the sinks, where I reached out with my free hand and turned on the water full blast. He was half-falling down already, so it wasn’t hard to get his head under the faucet. In a second he was struggling and sputtering, but together we held him in place. Once he realized that I wasn’t trying to drown him—and that the purple water swirling down the drain was taking Glitch gunk with it—he relaxed and held still.

I pumped soap into my hand and spread it on his face. “Rub that in. It’ll help.”

I went over to the dispenser to grab some paper towels. As soon as my back was turned, Milsap yelped. There was a splash and some gurgling sounds. I spun around, paper towels in hand, to see Tina holding Milsap’s head down in the sink. Water poured out of the faucet and splashed over the basin’s rim onto the floor.

“Tina! No waterboarding the client!”

She grabbed Milsap’s hair with her left hand and wrenched him upward as she waved some papers, folded lengthwise, at me. Milsap gulped in air, trembling.

“It’s your contract. I told you he stole it.” She plunged his face back into the sink.

“Okay, you got it back. Stop.”

I went to the sink and unblocked the drain, then untangled Tina’s hand from Milsap’s hair. He coughed and gasped, and I waved Tina back a few steps.

“Damn it, he broke my nail with his head,” she said, inspecting her hand. “It won’t grow back, you know. I’ll have to get acrylic. Add it to his bill, Vicky.”

I ignored her. You can’t fight demons if you’re worried about breaking a nail.

Milsap braced both hands on the sink, then raised his dripping head. Hunched over, he peered into the mirror. He looked terrible. His bloodshot eyes blinked above bags you could pack groceries in, scratches crisscrossed his cheeks and neck, and a faint purple stain blotched his face like a birthmark. His wild Einstein mane, matted and streaked with purple, looked like a costume-shop fright wig someone had left out in the rain.

“What was that thing?” he rasped, fingering a purple strand of hair.

“The Glitch? You know what it was. You hired me to kill it.”

“Professor Milsap doesn’t believe in demons.” Tina stepped forward, and Milsap cringed. “He doesn’t believe in me, either.”

“I do, I do!” He ducked like he wanted to hide under the sink. “Keep away from me! You’ve more than proved your existence.”

“Tina, grab me some paper towels,” I said. “Hang on, Professor. We’re almost done.”

Tina yanked hard enough on the towels to pull the dispenser off the wall. It landed with a crash, making Milsap duck again, his arms protecting his head. She stomped across the room and threw the towels at the professor. They fluttered around him like autumn leaves.

“He said everyone in Deadtown is either a psycho or a fraud.” Deadtown was Boston’s paranormal zone. All zombies, werewolves, vampires, and other assorted creatures of the night—including shapeshifters like me—were required by law to live there. Tina scooped up some paper towels threw them at Milsap again. “Look at me! Does this look like something I’d fake?” She raised her arms to shoulder height, palms up.

Not what you’d call a pretty sight. Like all zombies, Tina had spongy, gray-green skin and bloodred eyes. But the rest of her—the lashes gummy with mascara, the Barbie fashion sense, the double ponytails sprouting from the top of her head—that was 100 percent Tina. Her point was obvious: She’d rather be a normal teenager than a monster. Who wouldn’t?

Milsap straightened; he’d decided it was time to regain some of his dignity. “I never called you a fraud, young lady. Your condition is the result of a virus. It’s been documented, even if we don’t yet understand it completely. What I said was that Boston’s so-called ‘werewolves’ and ‘vampires’ were either charlatans or deluded.” He turned to me, lifting his eyebrows with earnestness. “I am a man of science, Ms. Vaughn. It is not possible for a corpse to return from the grave and survive on human blood. It is not possible for a human being to transform into a wolf for three nights each month. The laws of physics, not to mention biology, proscribe it. Whatever psychological aberration these people suffer does not, cannot affect their physical reality.”

Psychological aberration, huh? I was starting to feel like dunking the guy’s head myself. I’m not a werewolf, but I do change form. As one of the Cerddorion, a race of shapeshifting demon fighters that stretches all the way back to the Welsh goddess Ceridwen, I can change into any creature, three shifts per lunar cycle—the laws of physics and biology be damned. Maybe there were some things science hadn’t caught up with yet.

“You saw the demon,” I pointed out, bending over to gather some paper towels. I crumpled the towels into a ball and wet them at another sink.

“I don’t know what I saw. Some kind of animal, perhaps, that escaped from one of the biological research labs.” His expression turned defiant. “I do know, however, that demons do not exist. I opposed the trustees’ decision to hire you. I only volunteered to be your contact because I didn’t trust you. I fully expected you’d crash around the computer room for a while, causing untold damage, and then claim you’d driven out the ‘demon’”—his voice went all sarcastic with the word—“after you’d wreaked so much destruction that the so-called Glitch would be moot. So tonight I left this young lady in my office—”

“Locked me in, you mean.”

“—and I went to the security surveillance station to see what you were up to. The officer was sprawled across the desk, and snoring. I woke him, and we both saw you disable the camera. We rushed to the lab before you could do worse.” His glare was just this side of murderous.

“Whoa, Professor.” I held out both hands in a calm-down gesture. “I didn’t disable anything. That was the Glitch. I sprayed the camera to pull it out of your surveillance system. It fried the camera when it came out.”

“That’s impossible.”

“You are so lame!” sputtered Tina. “That Glitch zapped you halfway into next week, it clawed your face all to hell, you’ve got Glitch spit gooping up your hair—and you keep saying there’s no such thing. How can you be so stupid?”

Milsap gaped at her, his face a mixture of dumbfounded dropped-jaw and angry-furrowed forehead. As if never in his whole life had anyone called him stupid before.

“Whatever.” Tina dismissed him with a wave of her hand. “I saw a vending machine back there, Vicky. I’m getting something to eat.” She’d have slammed the door behind her if it wasn’t the self-closing kind.

Zombies are always hungry. Now that I thought of it, I’d never seen Tina go so long without a snack—or twelve. It’d be good for her to work off her emotions by chomping down twenty or thirty chocolate bars.

Milsap stared after her. “Next, you people will be telling me the library is haunted by the ghost of some undergraduate who perished in the stacks.”

“Don’t be ridiculous, Professor.” He blinked at me like a purple-spotted owl. “Everyone knows there’s no such thing as ghosts.”

He kept blinking, like he couldn’t tell whether I was kidding or not.

I approached him with the sodden mass of paper towels. “Let me get a look at you.” He leaned over the sink again, turning his head so the spit-covered side was toward me. I used the paper towels to scrub more of the gunk from his face. I can’t say I was all that gentle—I mean, the guy had tried to rip me off and have me arrested. He winced, but he didn’t complain. I inspected the slashes on his cheek where the Glitch had clawed him, checking the broken skin for specks of venom. I dabbed at a couple of spots with the paper towels, lifting the poison out, then rubbed in more soap. Milsap flinched as the soap stung him. Another rinse, and I checked again.

“That’s the best we can do for now,” I said. “I cleaned the venom out of the cuts, but keep scrubbing your face until there’s no trace of purple left. It’ll take a day or two to get rid of it, but you should be okay as long as it’s completely gone in a week. It takes about that long for the poison to work.”

He straightened again and glanced in the mirror. “And my hair?”

“Wash it a hundred times, shave it off, whatever. You could even leave it in for a new look—if you can stand the smell. The stuff in your hair won’t hurt you. But get it off your skin.”

A tremendous crash shuddered the bathroom door. Tina must have been awfully hungry—it sounded like she’d torn the front off the vending machine and hurled it down the hallway. Well, why not? Like I said, zombies are always hungry. And she’d already wrecked her manicure.