Title: Catalyst
Author: csiAngel
Rating: K+
Disclaimer: I do not own Lie to me*
Spoilers: Non-specific. Does not spoil the latest episodes.
Summary: Sometimes it takes a catalyst to initiate a reaction…
Dedication: Happy birthday, DNAisUnique! As a little gift to you, a response to your prompt for Cal/Gillian - one catching the other in a compromising position. I hope this fits!

… … …

After giving a quick cursory knock, Cal swung open the door to Gillian's office and stepped inside.

He stopped immediately.

If he had been looking through the window of the door before he entered then he would have seen that he should wait. As it was, he had been looking down the corridor and wondering if he actually wanted to know why Loker and Torres were carrying a giant teddy bear.

In future he would pay attention to where he was going.

"Sorry," he muttered, hoping that the only emotion Gillian had noticed on his face was remorse. She and her visitor were both looking at him, and Gillian had taken a step back, away from her 'friend', but it didn't take a body language expert to figure out what he had walked in on. "I'll come back later," he told her with a nod, and he quickly left the room.

As he walked back to his office, his mind raced with what had just happened.

It was a surprise. He hadn't realised that Gillian had been dating anyone. He should have expected it. Months had passed since her divorce and she was an incredibly attractive woman. Of course she would have met someone.

The anger he felt, he knew was unjustified, although if he aimed it at himself then it certainly had a place. He had known for years that he was falling for Gillian. He had kept his distance; hidden his feelings; buried his fury and frustration as he had to watch Alec deceive her. And even now, months after she had become officially single again, he had been telling himself that it was better if she didn't know: That he wasn't good enough and she deserved so much more.

There had been occasions when he thought he saw a deep affection in her eyes - he wouldn't let himself think that it was love. But she had never said anything, and she was his blind spot: He couldn't be sure that he was fully understanding everything he saw. The scene he had just interrupted definitely implied that she did not share his feelings.

He dropped into the chair behind his desk and picked up a pen; resting it between his fingers, then tapping it against one hand. Pushing past his jealousy, he recalled the scene, calling an image of Gillian's 'friend' to mind so he could see if he could place him, and figure out when they had met. Cal hoped that the guy wasn't really as dark and handsome as he was remembering him to be. The more he thought about it, the more he thought that the face was familiar, but he couldn't bring to mind an explanation for where he had seen it before.

Cal didn't know how long he had been dwelling on the thought of Gillian with someone else, but he was interrupted by the woman herself coming into his office.

"Hey," she greeted him with a hesitant smile and even from across his office he could see that she was embarrassed.

"Hi, love," he returned, sitting forward in his chair and smiling at her as if everything was fine.

Gillian's lips curved into an amused smile and she shook her head slowly. "As you won't ask," she said as she approached his desk, "I'll tell you. I met Mark last week, when I went out with Ellie and Clare."

Cal nodded to show that he remembered her evening out with her girlfriends; he actually had no desire to hear the story of Gillian and 'Mark'.

Gillian sat down opposite Cal and continued, "We had dinner on Saturday and we were going to go to dinner this evening… That's why he was here."

Cal found a little hope in Gillian's choice of words. We were going to go… That sounded like they no longer were. Though he did feel bad for wishing away Gillian's date.

"You don't have to explain anything to me, love," he told her, leaning back in his chair and trying not to feel too pleased that Gillian's plans had changed.

A knowing smirk accompanied her next words. She knew exactly what was going on in his head.

"Wouldn't want your imagination running away with you," she remarked, and Cal smiled at the sparkle in her eyes. Whatever the reason for her change of plans, Gillian wasn't unhappy about it.

Unless, of course, her plans had just been postponed, and not cancelled. Cal's smile faltered as he came to that realisation. And he had to consciously stop it from falling completely when it occurred to him that 'Mark' may still be waiting in Gillian's office.

"Well now I know that," he said, trying to sound normal, "I'll set my imagination to explaining what Loker and Torres are doing with a giant teddy bear."

Gillian frowned - so apparently she didn't know either.

Despite his attempt at distraction, Cal's thoughts wouldn't be kept from Gillian's love life for long and he couldn't resist saying, "You don't want to keep 'Mark' waiting, love."

"He's gone…" she informed him with a small shrug, but he could see a smug glint in her eyes. She was intentionally withholding information from him. "A giant teddy bear?" she queried.

He ignored her attempt at deflection. "He's gone? I hope you didn't think I needed you for work, I was just popping by to see if you knew what was going on with the bear -"

Gillian shook her head and Cal stopped the lame lie he knew she would not be buying.

"We just agreed that it wasn't going to work." She ended with another shrug.

Cal was torn between smiling with relief and frowning. There was something more to what Gillian was saying. She still hadn't told him the whole truth.

"Do you want to talk about it, love?" he asked, concerned, and feeling rather guilty about being pleased.

Gillian held his gaze but didn't answer. She seemed to become lost in her thoughts.

… … …

Gillian led Mark into her office and closed the door behind them. She had been slightly nervous all day about their date that night. She liked Mark. He was funny and polite, and definitely attractive, and she had enjoyed dinner on Saturday. But something had been niggling at her all day, and she had been unable to determine what it was.

And her anxiety had not been helped by the fact that when she met him in the foyer a minute ago, Mark seemed a little uncertain himself.

She turned to face him and forced a confident smile.

"You didn't fully realise what I do for a living, did you?" she asked him when his eyes fell on hers after looking round her office.

He smiled sheepishly. "I know what the Lightman Group does I just -"

Gillian shook her head. "It's okay. I understand that it's… off putting."

"Oh no," he said, stepping closer to her, "Sorry, please don't think that I'm being scared away. I'm sure it would take some getting used to to have a partner who can read your every thought… But I have a feeling you'd be worth it."

Gillian felt a blush creep up her cheeks, and butterflies fluttered in her stomach; yet, the niggling remained.

"I just hadn't realised that you were… the boss," he continued.

Gillian nodded. "Well I'm -"

"Cal Lightman's partner," he finished for her.

Gillian felt herself shift into defensive mode. Her back straightened and her jaw set squarely. "You know Cal?" she asked.

"I've met him," he answered her, seemingly unaware that she was ready to kick him out if he so much as thought about speaking ill of Cal. "… Actually, I teach Emily Lightman."

She hadn't seen that coming. "Oh…"

"I didn't mention it when you said you work here because I imagined the Lightman Group to have hundreds of employees and figured you probably didn't even know Cal Lightman himself… I didn't realise you were the Gillian."

Gillian frowned. "The Gillian?" she echoed.

"I overhear Emily and her friends talking… I'm a cool teacher, I let them talk while they work," he smiled, and Gillian felt her earlier tension ebb away. He fixed his eyes on her with a look that was mixture of admiration and sadness. "She adores you," he told her.

Gillian's eyes widened and she smiled fondly. "Well… I adore her."

Mark nodded and the disappointment in his eyes deepened. "And from what I hear… her father is quite fond of you as well."

"Ah…" Gillian wasn't sure what to say in response to that.

"And I don't need your training to know what that look means." He laughed as he made the comment, but she knew it wasn't out of humour. "I don't want to get in the middle of that."

And in that instant, Gillian understood what it was that had been causing her feeling of unrest all day: She didn't want anyone to get in the middle of that either.

"I'm sorry," she told him, her apology an honest one. "Cal and I have never been more than friends -"

"Oh I know that too," he quipped.

At Gillian's raised eyebrow, he added, "Emily and her friends talk a lot!... I probably should have a word with them about that…"

Gillian laughed, and shook her head at how nice he was being about this. If she wasn't so ridiculously in love with her best friend and business partner, she would definitely like to explore what could have been between them.

"I'm sorry, Mark… I didn't - … Well, I didn't expect to meet anyone, and then I didn't expect to like you so much, and then I - … I thought I could do this."

Mark nodded understandingly again. "That's because you're in denial about your true feelings."

Gillian could tell from the teasing expression on his face that he was quoting Emily and her friends. She laughed out loud, and commented, "Maybe I should have a word with Emily about discussing my love life - or absence of, or whatever - in class."

Mark shot her a wistful smile. "She's made a good choice for her Dad."

She offered him a soft smile of gratitude in return. "Thank you."

"I'm glad I met you, Gillian Foster…" he told her as he stepped forward again and leaned in to plant a gentle kiss on her left cheek.

… … …

"Earth to Gillian," Cal prompted when Gillian had been silently staring at him for what felt like half an hour.

She shook her head as if snapping out of a daze and gave an apologetic smile. "Sorry. What was the question?"

Cal frowned, wondering what on Earth had had her so enraptured. "Do you want to talk about what happened with 'Mark'?"

He thought he saw her begin to smile but it quickly vanished and she looked deadly serious as she asked him, "Why do you say his name like that?"

"Like what?" he shrugged though he knew exactly what she meant.

"Like it isn't really his name."

He pleaded ignorance. "Don't know what you mean, love. Maybe it's the way you're hearing it."

This time she did smile, but she ducked her head to hide it.

Cal watched, his curiosity piqued. She didn't seem particularly unhappy to have ended things with 'Mark' and yet she was acting quite mysteriously.

"Am I missing something?" he enquired, his brow furrowed as he watched her carefully.

She looked up at him and he was just thinking that he was going to lose her to her thoughts again when she nodded once and replied, "Probably."

This only confused him further. "Are you going to help me out?"

Her eyes darted to his as he finished speaking, as if she was surprised by his words. But, again, she didn't say anything.

… … …

They both watched Cal leave and then slowly turned to face each other.

"You don't need training to recognise that emotion either," Mark remarked. "I was kind of hoping Emily was wrong about the two of you." He gave a half smile and angled his head in the direction of the door. "I'll go so you can go and explain."

"That's going to be… interesting."

"Maybe I'll be the catalyst he needs to tell you how he really feels."

Gillian shook her head. "That's unlikely."

Mark appeared to study her for a moment and then he said, "I think I can understand why the two of you are 'in denial'… I'd be terrified of losing you, and convinced that there's no way you could share my feelings…"

Gillian could feel herself blushing again.

"Help him out."

Her eyes grew wide. "You want me to make the first move?"

He shrugged. "I'd hate to think that I gave you up so the two of you could spend a few more years hiding your feelings… And I'd know! Because Emily and her friends would keep me up to speed."

Gillian laughed, but she still wasn't entirely convinced of the sensibility of his suggestion.

"I know we've only known each other a week… But I like you, Gillian. And you deserve to be happy."

He kissed her cheek again, and this time they were not interrupted.

"Think about it… I'll be listening."

… … …

"Are you sure you're okay, love?" Cal asked Gillian, pulling her out of her thoughts again.

Her eyes met his and she nodded once. "We decided it wouldn't work because Mark's one of Emily's teachers."

Cal's eyebrows rose. "I see…" That explained why he recognised 'Mark'. "Well there's no law against a teacher dating his student's father's business partner."

"No," Gillian agreed, "But he didn't think Emily would be very happy about it."

Cal felt a stirring of pride for his daughter, but voiced, "It's not up to Emily who you date."

Gillian nodded. "No, I know… But she has some opinions on it."

Cal tried not to react to that. He knew exactly what Emily's opinion was because she shared it with him on a near-daily basis.

"And, evidently, she discusses these thoughts in class, with her friends."

Cal hoped that his second surge of pride was suitably hidden behind an apology that wasn't entirely false. "Ah… Sorry, love. Do you want me to have a word with her?"

Gillian shook her head. "No, no, it's fine. But you can see why Mark thought it best not to get involved."

"Do you want me to have a word with him? Assure him I'm not a threat," Cal suggested, trying to be supportive rather than insanely jealous.

Gillian apparently found this amusing and giggled adorably.

"What's so funny?" Cal asked while enjoying watching her laugh.

"I was just picturing you 'having a word' without appearing threatening," she grinned.

"You don't think I could do it?" He feigned hurt.

"I don't think you want to do it… But that's okay, because I don't want you to. Mark understands the situation. It's fine."

"Are you sure?"

She nodded. "I'm sure… Although I was looking forward to going on a date tonight."

Cal did his best not to frown - that sounded like an invitation. "Well that can be arranged, love," he offered, prepared to tread carefully in case he had misread the situation.

Gillian raised her eyebrows but he saw the hints of a victorious smile on her lips: He hadn't misread anything.

"Are you asking me out?" she asked him.

"I think you asked me out, darlin'," he replied.

She pretended to be deep in thought for a moment. "I don't think so."

"So if neither of us asked, then are we going out tonight?"

"Is that you asking me out?" she quipped, a bright smile forming across her lips, and twinkling in her eyes.

Cal chuckled to himself. "You're determined that I'm going to do the asking, aren't you?"

Gillian shrugged, exaggeratedly coyly. "That's the way it always happens in my romance novels."

This too amused Cal, but the gravity of what they were discussing didn't escape his notice.

"Would it be a good idea?" he asked, seriously.

Brought back to the reality of the situation by his question, Gillian considered it for a second or so then replied, "Maybe."

Cal knew what accompanied that. "Maybe not."

He saw disappointment cloud her eyes but in true Gillian style, she quickly replaced it with hope. "But wouldn't you like to find out?"

Cal grinned in anticipation of her reaction to his next words. "Are you asking me out, love?"

As expected she laughed, such a beautiful sound that he could never tire of hearing. "We could be here all night," she commented, shaking her head, slowly.

"We could." Decisively, Cal stood up from his seat and walked round to stand in front of Gillian. "What do you say we discuss it over dinner?"

She looked up at him and her smile made him want to pick her up and twirl her around in excitement. He made a mental note to thank Mark for cancelling their date; and to thank Emily for discussing her old dad's love life at school.

She stood up, bringing her to merely a foot in front of him and Cal felt his heart skip with anticipation.

"I thought you'd never ask."

THE END