Arthur and Ariadne work because they are both architects.
She creates landscapes-cities and skyscrapers and bridges and roads stretching endlessly across the page, disappearing into the horizon. When the laws of physics can be ignored and the financial restrictions of her clients are entirely absent, she is free to design. Nothing is off limits. She can draw a paradoxical staircase and a mechanically impossible high-rise and nothing will stop her. She loves this freedom, this uncensored creation. It allows her to feel the limitlessness of the human imagination. Uncontrolled, uninhibited by the rules to which the physical world is bound, she can only be checked by the constraints of her own mind.
Arthur plans. He infuses the reality into their creations. His favorite paradoxes are the most concretely logical-the Penrose steps, a never-ending loop drawing its climbers into an unwinnable race; the tessellations of M.C. Escher, geometric representations of fascinating shapes and their combinations; the impossibly stacked triangles and squares and cubes that look different from every angle. He loves to understand how these paradoxes will work, how Ariadne will combine them to form an unconquerable maze that will baffle the subjects in each dream. He is the architect of the grander scheme, of how they will accomplish their goal without detection. He takes her creativity and structures it into a dream world where the wild imagination complements the careful layout.
They work because together they balance a scale. Arthur could use a little freedom in his life; Ariadne could use a little structure.
Most days, she lies on her stomach in front of the couch in their apartment, her feet occasionally bouncing in the air behind her as she sketches enthusiastically on her graph paper. He sits at his desk across the room with his laptop and his notepad, researching and strategizing. When his mind needs a break, his eyes wander to the bright socks barely visible over the edge of the couch, and he smiles. On longer breaks, he steps quietly around the sofa to run a hand softly over her lower back and press a kiss to her temple before eyeing her empty mug and offering to make another pot of coffee. Usually, it's been a few hours since she remembered to eat or drink, and she accepts the caffeine boost gratefully.
When the coffee has brewed, Arthur returns with two steaming mugs and sits cross-legged on the floor with her, even though he isn't fond of the wrinkles that sitting like that produces across his suit pants. (He doesn't really need to be dressed nicely when they're just working from home, but he's Arthur, and it's habit, second nature.) He glances at her sketches for a moment, and they talk about their work, about new ideas, for a few moments. Then, they move on, leave work behind. They talk about everything—their childhoods, their friends, that lovely café they'll have to go back to next weekend. It's how they got to know each other, when they first started dating, these technically unplanned yet wordlessly agreed upon conversations. They'll never know everything about each other, but these times are so comfortable and enjoyable that they will never tire of trying. They're companions in every sense of the word; they are both the other's best friend.
After coffee, they work a little longer—one, maybe two hours. When they stop for the day, Arthur closes his computer and files away his notes, then smiles at Ariadne as she organizes her drawings into what he supposes she thinks is some sort of order.
On days when they're feeling isolated, Ariadne grabs a warm, brightly colored cardigan and they enter Paris hand in hand, wandering down streets until they find a restaurant that appeals. They laugh and smile through dinner, fingers brushing together often, and enjoy the lights and sounds and chaos of the city. Arthur slips an arm around her waist as they wander back to their home while Ariadne stretches her arms up to point out and admire interesting architecture. He follows her on her path through the city, only contributing to the decisions about their direction when it is vital that his logic tempers her impulsiveness.
As darkness falls, the temperature in the city drops down with the sun. The first time he offered her his jacket, she rejected it with a good-natured grin. Later that night, as the temperature continued to fall, she conceded that it wouldn't be such a bad thing, so long as he didn't get any ideas. He asked what she could possibly mean by that while quickly moving to drape his jacket around her and pulling her close, one hand rubbing against her arm for the heat of friction. She shoved his shoulder playfully and replied that he knew exactly what she had meant, before snuggling back into his chest with a contented sigh.
Other days, they are happy to be hidden away together and decide to stay at home. After they finish their work and Ariadne's papers are in some semblance of a pile, Arthur offers her a hand to help her off the floor and they walk together to the kitchen. He, ever the planner, takes stock of what they have in the refrigerator and suggests meals. They decide what to make and she watches him cook, his shirt cuffs rolled up and his usually gelled hair beginning to escape its prison. She often leans over to drop in some new ingredient, giggling when he simply stirs it in with the rest, so used to her additions by now that he's learned to trust them. They continue to talk about anything that comes up as she slices and juices and chops ingredients and he adds them to their food. Occasionally, when dinner is ready, they stay at the counter and eat happily, wine glasses between them on the light surface as they lean closer every few minutes for a kiss. Sometimes, the food is forgotten as they get caught up in each other, her hands freeing the last of his hair from its calculated style, his sliding across her neck and arms, pulling her closer to him. He always ends up backed against the counter, the lights of the city sparkling in his eyes; she always ends up on her tip-toes to make up for their substantial height difference, the shimmering lights of the city reflecting off her back through the window.
When they end up eating at their table, they stare out at their beautiful city and enjoy it alone, together. This is different from those cafes; the sparkling colors and magnificent structures seem all their own now in the privacy of their home. They knock their wine glasses together with equally wide smiles, perfectly content.
They support each other, support each other's efforts and hopes and dreams. They enjoy each other, enjoy the way they feel so complete and fulfilled and happy. They thrive off each other, off the lifestyle they have created that is absolutely perfect for them. They love each other. And because they are wonderfully complementary, half spontaneity and half contemplation, half imaginative creation and half strategic preparation, they work. Together, they can build a world.