Now I know what an animal feels like. An animal stalking its prey.

Gaia Moore paced back and forth across the narrow foyer, staring at the front door. Every muscle was tensed in a state of readiness. Yes... she was like a tiger. Or a wolf. Her blue eyes were slits behind a shroud of tangled blond hair. Her sneakers barely made a sound on the worn strip of carpet. Her heart pounded in near perfect rhythm to the ticking grandfather clock. The Nivens' brownstone was cold and dark, but her skin felt very hot. She'd deliberately left the lights off. She didn't want Ella to know that anyone was home. She wanted to catch Ella completely by surprise -- because as every black belt knew, surprise was the key to a quick defeat.

Not that Gaia imagined she would have any problems beating the shit out of her foster mother. But still, one could never be too careful--

There was a click, and Gaia froze.

Her eyes zeroed in on the front doorknob. It was turning. This is it. She held her breath. She could see Ella's silhouette through the panes of frosted glass -- a dark figure against the glare of afternoon winter sunlight.

The stepmonster was home.

Ella pushed open the door, fumbling with a bunch of paper bags -- no doubt filled with miniskirts or lingerie from some overpriced designer store that catered to women about ten years younger than she was. But Gaia's attention wasn't focused on Ella's belongings. No... her gaze remained pinned to Ella's vacant green eyes.

All at once, Ella flinched.

The door slammed shut behind her. She stiffened and shot Gaia a baffled stare, frowning. Her bags dropped to the floor.

"What are you doing here?" Ella spat. "Why aren't you in school --"

"Does George know you sleep around?" Gaia interrupted. She was shocked at the sound of her own voice. It was cold, hoarse -- the voice of a stranger.

Ella blinked. For an instant a fleeting smile crossed her face. Then she sighed and began unwrapping her scarf. "Excuse me?" she said.

"You heard me," Gaia croaked.

"Does George know I sleep around?" Ella echoed, pursing her collagen-enhanced lips. Her tone was flat, impossible to read. She shrugged gracefully out of her short fur jacket and crossed to the front hall closet, stepping within inches of Gaia's clenched fists. "You know, that's a pretty offensive accusation, Gaia. Even for you."

"Not half as offensive as your having sex with Sam Moon," Gaia hissed. Her voice shook with rage. Ella was so close. Gaia felt her legs dipping into a combat stance, as if acting of their own volition: muscles coiled, feet flat, knees bent. Her body was preparing itself to fight.

Ella just shook her head. With her back turned, she hung up her coat -- almost as if she were taunting Gaia, daring her to strike. Then she closed the closet door and glanced over her shoulder. A satisfied grin slowly spread across her face.

"Boys will be boys," she murmured.

Gaia gaped at her. For a moment her body went slack. She couldn't believe it. Ella wasn't even trying to deny that the affair had taken place. This was crazy. Whatever Gaia had been expecting, it wasn't this blatant, icy, arrogant up yours. Usually when Gaia caught Ella in a lie, the woman would scream or spew threats -- and her face would twist with fear and rage.

But Ella didn't even look troubled. She met Gaia's gaze head-on. Gaia thought she had seen every single mask of deception that Ella had ever worn: a thousand different faces for a thousand different situations. But this victorious expression was one Gaia had never seen before... which made it all the more disturbing.

"What's the matter?" Ella whispered.

Gaia swallowed. Fizzy threads of adrenaline began to snake through her veins. "You, you -- you bitch," she stammered, unable to form a coherent thought through the haze of anger.

"Why don't you just face what's really bothering you?" Ella asked matter-of-factly. She cocked her head and lowered her voice. "It's not that I cheated on George. That's for damn sure. So you can drop the high-and-mighty act. What's bothering you is that Sam Moon made love to me. To me," she repeated. Her smile widened.

Gaia's entire body now hummed with a pulsating electric energy. Various kung fu and karate techniques whirled through her mind. She would choose the most painful form of attack. Ella's self-involved little rant would end in the shattering of bones....

"I know what he tastes like," Ella continued, whispering. "I know what he feels like. What he smells like. I know what sounds he makes --"

"Hai!" Gaia cried, lashing out with a right jump kick.

But to Gaia's utter shock, Ella jumped backward and expertly dodged the strike.

Gaia caught a glimpse of a strange, amused smirk on Ella's face. What the hell? Gaia bit her lip. But there was no time to ask herself questions. Focus! she savagely screamed at herself. Ella had just gotten lucky. That was all. Her luck wouldn't last, though. Gaia had telegraphed that first kick. She wouldn't make the same mistake twice....

The next instant Gaia feinted with her left hand -- then arced her right fist hard into Ella's ribs. There was a satisfying thunk and a sharp intake of breath, and Ella quit smiling. But before Gaia had a chance to follow through, Ella spun in a circle. She was a blur of arms and legs. Her right hand darted out and seized Gaia's left forearm, as quickly as a cobra's pouncing on a mouse.

"Hey!" Gaia protested. "What --"

Before Gaia knew it, she found herself being flung to the ground. The back of her head struck the floor with a sickening crack. A white flash exploded in front of her eyes. Shit. Luckily it was one of those rare moments when she felt blessed to be fearless. Because she knew she should be terrified. She was losing this fight. To Ella.

But all she felt was a cool, detached numbness. And pain.

Get up, an instinctive voice commanded.

She rolled -- a fraction of a second before Ella kicked at her head -- then sprang to her feet. Her breath came fast. Instantly she assessed the natural advantages she had: She was taller than Ella; she had longer arms and legs. She was also stronger, but she knew that mere strength could work against a person in combat.

Keeping her left fist close to her body, she punched with her right and caught Ella on the side of the head, feeling the hard skull beneath her knuckles. But Ella punched simultaneously: a left. Gaia blocked it and tried to sweep Ella's feet out from under her. Ella nimbly sidestepped the kick, then aimed a left-right-left combination that whistled past Gaia's cheekbone with an audible whoosh.

"You can fight," Gaia whispered out loud.

She stepped back. Something else was at work here. Yes. A terrible realization was creeping through her mind: This stupid bimbo was trained in martial arts. There was no doubt about it: Ella knew karate, kung fu, probably jujitsu as well. Her reflexes were perfectly honed. Underneath her soft-looking, hyperfeminine curves lay steel-hard muscles. Which meant that Ella wasn't a bimbo at all. Of course, Gaia had recently come to suspect that Ella was smarter than she pretended to be -- but she'd never once imagined that Ella had been hiding abilities like these.

Ella smiled again, clearly sensing Gaia's bewilderment.

"Who are you?" Gaia found herself asking.

Instead of answering, Ella lunged forward with a barrage of chops and sidekicks. Gaia backtracked down the shadowy hall, blocking each successive strike. Ella's speed and accuracy were astonishing. And the brutal style of her attack betrayed a demonic viciousness Gaia had never seen before in an opponent -- not even in the man who had killed Mary or that other guy who had attacked her in the park a few nights ago....

"Who are you?" Gaia grunted again.

"You know who I am," Ella whispered. "I'm the woman Sam loves."