A/N: I usually prefer to write stories where there is a little more action, but this popped into my head after "Taken" (with the Flash crossovers I never know if that's 4X15 or 4X16) and almost wrote itself. I really liked that episode and the choices they made for Felicity. Of all the reasons to be upset with Oliver for hiding William, his unwillingness to include her, to lean on her, felt adult and felt right.

I would still like to do something with Guest's suggestion of "The Butterfly Effect," but nothing is coming to me at the moment. We'll see.

If you're interested in other takes on Felicity learning about William, I'd strongly recommend "Coming Down to Nothing." The premise is so good I wish I'd thought of it (darn it) and it's really well written.


Entropy refers to the idea that everything in the universe inexorably moves from order to disorder.

The date almost slipped by without his notice. There was the usual amount of crazy going on plus a little extra, and it was evening before he glanced at the calendar and recognized the day. When he did, he was ashamed of himself for forgetting.

Two years. It had been two years since the death of his mother. Two years since she had faced Slade Wilson with a mother's courage to protect her children above all else. He was surprised that Thea hadn't mentioned anything, but then again she'd had her own set of crazy to deal with lately. Unlike him, she still had one living parent, but Oliver was pretty sure that only made things worse. Given the choice between Merlyn and no parent – well, no parent seemed like a pretty good option. In fact, now that he really knew Malcolm Merlyn, he was amazed that Tommy had turned out as well-adjusted as he had. He wished his friend were still alive so that he could tell him so.

Not that his mother had exactly been sweetness and light. Calling her complicated was a little like saying that Mount Everest was a big mountain. She had been capable of great bravery. And she had been capable of – if not causing great evil – at least being a party to it, of watching it unfold and maybe even giving it a little push. The problem with having such a parent, he thought, was that you never knew whether you were supposed to follow any of their parental advice. Because…seriously… should you really be taking lessons in respect, decency and the benefits of hard work from an individual who was in part responsible for the deaths of 500 of your fellow citizens? She was hardly a role model.

Nevertheless, on this anniversary of her death he found himself thinking about the things she had told him growing up. While neither of his parents had been intellectual slouches, he was certain now that his mother had been the more intelligent of the two, the one more capable of dissecting layers and working her way through nuances that his father missed. That difference had been apparent in their advice. His dad's had been pretty standard, as if he were reciting from the Handbook issued to all fathers on the birth of their son; work hard, deal with people fairly but don't be a sucker, be charitable up to a point, don't let your wife know about your mistress – that sort of thing. Of course, Dad had made up for his banality in the end with that doozy in the life raft, but that was really more about giving Oliver a mission than giving him a life lesson.

His mother, on the other hand, had dispensed advice that was less traditional and often more puzzling. It wasn't a daily occurrence – there were three or four big teaching moments a year – but when she did, she generally left him scratching his head. Unlike his dad, he didn't know what he what he was supposed to do after one of his mother's serious talks. They seemed more philosophical than directional. He typically filed her words away in the back of his brain, hoping that one day they might make more sense.

Two years after her death and a day after Felicity left him, some of those words came back to him with amazing clarity. Sitting in the too-quiet loft and looking out at the lights in Star City, he thought about what she had told him on his sixteenth birthday.

Sixteen was a big one and Oliver had been looking forward to it for months. Eighteen might be the legal hurdle to adulthood, but Oliver knew that sixteen was really the age at which you stopped being a child and began stepping into the grown-up world. It was the age at which you could drive, get a job (not that he planned on doing that), and – he was quite confident – get laid. You began making your own decisions at sixteen, and people had to respect those decisions. Hell, he was even beginning to look like an adult. The gangly boy was developing broad shoulders over a narrow waist, and his stick-thin arms now had biceps and triceps. And the girls were noticing.

He'd told his mother all that – well, minus the getting laid part – when she'd asked him why he was so excited about turning sixteen. She'd listened in silence, and continued to sit quietly with him for so long that he wasn't sure she was going to say anything. But in the end, of course, she had.

"Oliver, do you know one of the big differences between being a child and being an adult?" she'd asked in that careful, cool way of hers.

He'd grinned. "Yeah – all the things I just told you. A car, money, independence…"

She'd looked into his eyes and smiled – rather sadly, he'd thought – and shook her head. "Those are just show, Oliver, they're not the real difference."

"Oh?" What else could it be? He'd wondered if she'd read his mind about getting laid and was about to give him the responsible sex talk. (Dad had already done that – on his fourteenth birthday).

But, no, this was going to be one of her philosophical musings. "The difference, Oliver, between being a child and being an adult is that when you become an adult, very few things - including happiness - are ever pure again. They get complicated…and they tend to unravel. It's not that you won't ever be happy as an adult – you will, plenty of times. But even in your happiest moments there will be something that dilutes it, some little worry that stops it from being complete. Things in life have a way of coming apart. You don't see it as a child, but it's in your face every day as an adult. And when you're grown up, you have to work hard every day just to hold things together. Don't rush to give up childhood, Oliver. Once it's gone, it's gone forever."

Sixteen-year-old Oliver hadn't known what to say to that. It was kind of a downer on his big day, and that bit about happiness didn't seem right. He'd sat there and stared at her, certain that if he received the Porsche he'd hoped his father was going to give him, his happiness would be very pure indeed. This was just another puzzling piece of advice from Mom that was to be archived for a future date. Maybe he'd talk to Tommy about it - ask what his father had told him on his sixteenth birthday. It had to be better than a few vague words about keeping things from falling apart. He'd decided that he would ignore her and stay focused on what mattered – getting the Porsche and getting a girl in bed.

Grown-up Oliver noticed that a light rain was beginning to fall, blurring the windows in the loft and turning the lights below into a muted, softened version of Star City. Yesterday, he thought, he had known great happiness; he had felt his heart leap the way he'd always heard it could in songs and stories. He had seen Felicity, confirmed by at least four specialists to never walk again, stand up out of her wheelchair and move cautiously but most definitely on her own two feet. He had seen a miracle.

It was staggering. Oliver had experienced enough in his life to know that miracles were real; they positively happened. He also knew, however, that they were whimsical things, not always there when you needed them and astonishing you when you least expected them. Felicity getting out of that chair had been a needed miracle, a bonanza of good luck for the person he loved most in the world, the person who deserved nothing but good luck. And he had been happy – happier than receiving the Porsche on his sixteenth birthday, happier than getting laid for the first time, happier even than returning to Star City after being presumed dead for five years. He would never forget the look of awe on her face.

That happiness had lasted for all of five seconds. Because shortly after standing, she had used her newfound mobility to walk out on him, to carry herself to the door of the loft and leave. It had felt final, permanent. The look of awe on her face had been replaced by one of sorrow, and his pure happiness had unraveled, had come apart.

He recalled his mother's advice about working hard every day to hold things together. He'd believed that was what he'd been doing – holding the city together, holding Thea together, holding the secret of his son together – but apparently he'd taken his eye off the thing that mattered most. In some ways his relationship with Felicity was no less miraculous than her stepping out of that chair. The fact that a woman of strong convictions, who was smart, brave and beautiful, loved him unreservedly was every bit as amazing as a microchip that could make the paralyzed walk. He'd been a complete fuck-up for half his life and damaged goods for the other half, and she had somehow seen past all that to tie her life to his completely. And, stupidly, he'd taken that for granted.

He wondered what his mother would have thought about his engagement to Felicity. He was fairly certain his father would have liked her. Dad would have appreciated the fact that she never hesitated to call Oliver on his bullshit, that she was both strong and funny. Despite his responsibilities – or perhaps because of them – Robert Queen had been a man who valued a good laugh. Oliver was certain that Felicity would have provided more than a few chuckles during stilted family occasions, exactly when they were most needed. He could picture his dad grinning as she went off on one subject or another.

He wasn't so sure about his mother. She had always liked Laurel, but then Laurel had been perfect for Moira Queen, at least in the pre-island days. Laurel had been beautiful, serious, and ambitious, but not so smart that his mother couldn't manipulate her when she chose. Laurel had been anxious to please, the daughter of the local policeman wanting to get in the good graces of her boyfriend's wealthy, elegant mother. He had no doubt that Mom had capitalized on that, had made Laurel into a malleable ally in her quest to drive Oliver to be a responsible, successful adult.

Felicity, on the other hand, was not so easily controlled, despite being the lowly daughter of a Las Vegas cocktail waitress. Felicity had had the good sense to distrust his mother right from the start, and he doubted that Moira Queen would have been pleased with someone who could see through her machinations. Of course, in the end, when Mom had known he was the Arrow and was proud of him for it, he might have gotten her to come around about Felicity. He would have told her that Felicity was a big part of him becoming the man he was, that he couldn't have done any of it without her. His mother would have grown to value Felicity, even if she never totally warmed up to her. Above all, Moira had wanted what was best for her children. Felicity – clearly - was the best thing for Oliver.

Which meant that if Mom could give him advice at this moment, she would tell him that he had to stop things from unraveling; that he had to pull things back together, pull Felicity and himself back together. It wasn't going to be easy. Of all the reasons to pick for leaving him, she'd chosen one that was incredibly hard to fix. He'd expected her to be angry about the lie, to be hurt about him keeping secrets from her. He'd been confident he could smooth over that hurt in time. But his inability to lean on other people, to lean on his partner? That was another story. Running away to solve problems on his own was as natural as breathing to him. Maybe it stemmed from the number of times he'd been betrayed after the Gambit. Maybe it came from growing up in a house with two parents who were masters at keeping things to themselves. He was certain a psychologist would have a field day with it. But right now, he didn't have time for therapy to get at the root cause. He needed to change immediately. He needed to convince Felicity that he was willing to turn to her when things got complicated, that he was willing to lean on her. He just didn't know how to do it.

He decided he'd start by leaning on a friend.

He picked up his phone and called Diggle.