Softly falling snow blanketed Washington, D.C., adding a touch of lacy white trim to the elegant town houses lining a quiet side street just off Massachusetts Avenue. The few residents of the capital who weren't glued to their TV sets this Superbowl Sunday scurried by, chins down and collars turned up against the cold. Intent on getting out of the elements, they didn't give the town house set midway down the block a second glance. If they had, they might have noticed the discreet bronze plaque set beside the entrance that identified the offices of the president's special envoy.

Most Washington insiders believed the special envoy's position had been created several administrations ago to give a wealthy campaign contributor a fancy title and an important-sounding but meaningless title. Only a handful of the most senior cabinet officials knew that the special envoy secretly served in another, far more vital capacity.

From a specially shielded high-tech control center on the third floor of the town house, he directed a covert agency.

An agency whose initials comprised the last letter of the Greek alphabet, OMEGA. An agency that, as its name implied, sprang into action as a last resort when other, more established organizations, such as the CIA, the State Department or the military, couldn't respond.

Less than an hour ago, a call from the president had activated an OMEGA response. From various corners of the capital, a small cadre of dedicated professionals battled the snow-clogged streets to converge on the scene.

Maggie Sinclair unwrapped the wool scarf muffling her mouth and nose and stomped her calf-high boots to remove the last of the clinging snow. Stuffing the scarf in her pocket, she hurried through the tunnel that led to OMEGA's secret underground entrance. At the end of the passageway, she pressed a hand to a hidden sensor and waited impatiently for the computers to verify her palm-print. Seconds later, the titanium-shielded door hummed open. She took the stairs to the second floor and scanned the monitors set into the wall. Satisfied that only the special envoy's receptionist occupied the spacious outer area, she activated the sensors.

Gray-haired, grandmotherly Elizabeth Wells glanced up in surprise. "'My goodness, Chameleon, you got here fast.'"

"'I took the subway. I wasn't about to try driving through this mess.'' Shrugging out of her down jacket, Maggie hooked it on a bentwood coat tree. "'Besides, I wanted to leave my car for Red. Just in case.'"

Elizabeth's kind face folded into sympathetic lines. "'What a shame you were called in right in the middle of your father's visit. He doesn't get back to the States all that often, does he?'"

"'No, he doesn't.'"

Actually, Red Sinclair was lucky if he managed a quick trip stateside once a year. As superintendent of an oil- field exploration rig, the crusty widower traveled continually from one overseas job to the next. He might be drilling in Malaysia one week, Saudi Arabia the next.

"'And when he does come home,'' Maggie added with a grin, "'he usually times his visits to coincide with the Superbowl. I left him and Terence ensconced in front of the TV, alternately cheering the Cowboys and cursing the Redskins.'"

"'You left the poor man with Terence?'' A ripple of distaste crossed Elizabeth's face. Like most of the OMEGA team, she actively disliked the bug-eyed blue-and-orange- striped iguana a certain Central American colonel had given Maggie. The one time the receptionist had been pressed into lizard-sitting, the German shepherd-size creature had devoured her prized water lilies.

"'Honestly, dear, I don't understand how you can keep that...that creature as a house pet. I find him utterly repulsive.'"

"'Dad does, too,'' Maggie replied, laughing. "'Unfortunately, the reverse doesn't hold true. Terence hates this cold weather. He's been trying to climb into Red's lap to share his warmth, not to mention his beer, all afternoon long. I left them just before halftime, tussling for possession of a bottle of Coors.'"

"'Perhaps I should give your father a call,'' Elizabeth mused. "'If you're going out of town, he might like to get away from that disgusting reptile for a while. Maybe have dinner with me.'"

Maggie's brows rose. ""Am I going out of town?'' Elizabeth gave a little cluck of disgust at her uncharacteristic slip. Having served as personal assistant to OMEGA's director since the agency was founded, she knew when and how to keep secrets. She also knew how to use the Sig Sauer 9 mm pistol she kept in her upper-right-hand desk drawer. She'd fired the weapon only once in the line of duty, to deadly effect.

Maggie grinned to herself. This kind, lethal woman had a background and a personality as intriguing as her father's.

"'I wish you would give Dad a call, Elizabeth. I'm sure he'd enjoy having dinner with someone who doesn't prefer bugs as an appetizer.'"

The receptionist grimaced and reached for the intercom phone. "'I will, I promise. Right now, though, I'd better tell the chief you're here. He's waiting for you.'"

While Elizabeth announced her arrival, Maggie raked a hand through her snow-dampened, shoulder-length brown hair. A quick tug settled her faded maroon-and-gold Washington Redskins sweatshirt around her jeans-clad hips. This wasn't quite her standard professional attire, but the coded message summoning her to headquarters had signaled a matter of national importance, and she hadn't taken the time to change. Oh, well, OMEGA's director had seen her in worse rigs than this. Much worse.

Now all brisk efficiency, Elizabeth nodded. "'Go on in, dear.'"

As Maggie walked down the short corridor leading to the director's private office, a flicker of anticipation skipped through her, like a tiny electrical impulse darting across a circuit board. She tried to tell herself that her suddenly erratic pulse was due to her imminent mission, whatever it might be. Herself wasn't buying it. She knew darn well what was causing the shimmer of excitement in her blood.

He was waiting a few steps away.

Maggie paused outside the door to draw in a deep, steadying breath. The extra supply of air didn't do her any good. As soon as she walked into his office and caught her first glimpse of the tall, dark-haired man standing at the window, her lungs forgot to function.

After almost three years, Maggie thought wryly, she ought to be used to Adam Ridgeway's effect on her respiratory system. The sad fact was that each contact with this cool, authoritative, often irritating man left her more breathless than the last.

He turned and gave her one of his rare smiles. "'Hello, Maggie. Sorry I had to drag you away from the game.'"

She forced the air trapped in her chest cavity to circulate. Okay, the man looked like an ad for GQ in knife- pleated tan wool slacks, a white oxford shirt and a V- necked cashmere sweater in a deep indigo blue that matched his eyes. And, yes, the light from his desk lamp picked up a few delicious traces of silver in his black hair, traces he claimed she herself had put there.

But he was her boss, for heaven's sake, and she was too mature, too professional, to allow her growing fascination with Adam Ridgeway to complicate her relationship with the director of OMEGA. Unfortunately.

"'Hi, Adam,'' she replied, moving to her favorite perch on one corner of his massive mahogany conference table.

"'I don't mind the weather, but if the Skins lose this game because I'm not there to cheer them on, Red's going to gloat for the rest of his visit. He still can't believe I've transferred my allegiance from the Cowboys.'"

"'That is a pretty radical switch for an Oklahoman,'' the Boston-bred Adam concurred gravely.

"'No kidding! A lot of folks back home think it ranks right up there with abandoning your firstborn or setting fire to the flag.'"

Actually, Maggie's move to Washington three years ago had resulted in far more than a shift in allegiance in football teams. Until that time, she'd chaired the foreign language department at a small Midwestern college. An easy mastery of her work and a broken engagement had led to a growing restlessness. So when she received a late-night call from the strange little man Red Sinclair had once helped smuggle out of a war-torn oil sheikhdom, she'd been intrigued. That call had resulted in a secret trip to D.C. and, ultimately, her recruitment as an operative.

From the day she joined OMEGA, Maggie had never considered going back to sleepy little Yarnell College. What woman could be content teaching languages after leading a strike team into the jungles of Central America to take down a drug lord? Or after being trapped in a Soviet nuclear- missile silo with a brilliant, if incredibly clumsy, scientist? Or dangling hundreds of feet above the dark, crashing Mediterranean to extract a wounded agent from the subterranean lair of a megalomaniacal film star? Not this woman, at any rate.

Although...

If pressed, Maggie would have admitted that the life of a secret agent had its drawbacks. Like the fact that most of the men she associated with in her line of work were either drug dealers or thieves or general all-around sleazebags.

Oh, there were a few interesting prospects. A certain drop- dead-gorgeous Latin American colonel still called her whenever he was in D.C. And one or two operatives from other agencies she'd worked with had thrown out hints about wanting to know the woman behind the code name Chameleon. But none of these men possessed quite the right combination of qualities Maggie was looking for in a potential mate. Like a keen, incisive mind. A sense of adventure. A hint of danger in his smile. A great bod wasn't one of her absolute requirements, but it certainly wouldn't hurt.

So far Maggie had only met one man who came close to measuring up in all categories, and he was standing a few feet away from her right now. The problem was, whenever they came face-to-face, it was generally just before he sent her off to some far corner of the world.

As he was about to do now, apparently. "'So what's up, Adam?'' she asked. "'Why are we here?'"

"'I'm here because I got a call from the president an hour ago,'' he said slowly, his eyes on her face.

"'And?'' Maggie prompted.

The tingling tension that always gripped her at the start of a mission added to the fluttering in her veins that Adam's presence generated. Anticipation coursed through her, and her fingers gripped the smooth wood as she focused her full attention on his next words.

"'And you're here because you're going to impersonate the vice president for the next two weeks.'"

Maggie's jaw dropped. "'The vice president? Of the United States?'"

"'Of the United States.'"

"'Taylor Grant?'"

"'Taylor Grant.'' Maggie's astonishment exploded into shimmering, leaping excitement. In her varied career with OMEGA, she'd passed herself off as everything from a nun to a call girl. But this would be the first time she'd gone undercover in the topmost echelons of the executive branch.

"'Now this is my kind of assignment! The vice president of the United States!'' She shoved a hand through the thick sweep of her brown hair. "'What's the story, Adam?'"

"'For the last three months, the vice president has been working secretly on an international accord in response to terrorism. According to the president, the parties involved are close, very close, to hammering out the final details of an agreement. One that will send shock waves through the terrorist community. When this treaty is approved, all signatories will respond as one to any hostile act.'"

"'It's about time!'"

In the past few years, Maggie had seen firsthand the results of differing government approaches to terrorism. Depending on the personality of the people in high office, the response could be swift or maddeningly slow, strong or fatally indecisive.

"'The key players involved in crafting the treaty are gathering at Camp David to hammer out the final details,'' Adam continued. "'No one — I repeat, no one — outside of the president, the VP herself and a few trusted advisors know about this meeting.'"

Maggie eyed him shrewdly. "'So I'm to deflect the world's attention while this secret meeting takes place?'"

"'Exactly.'"

She chewed on her lower lip for a moment. "'Why me?'"

"'Why not?'' he countered, watching her face.

"'Mrs. Grant has at least half a dozen women assigned to her Secret Service detail,'' Maggie said bluntly. "'They know her personal habits and routine intimately. They wouldn't need the coaching I will to double for her.'"

"'True, but none of them matches her height and general physical characteristics as well as you do.'"