Paolo Giordano - The Solitude of Prime Numbers

She felt that something was being resolved, like a long wait coming to an end. She sensed it in her limbs, even in her bad leg, which usually never noticed anything.

Getting up was a natural gesture. She didn't even wonder if it was appropriate or not, if it was really her right to do so. It was only time, sliding and dragging itself after more time. Only obvious gestures that knew nothing of the future and the past.

She bent over Mattia and kissed him on the lips. She wasn't afraid of waking him, she kissed him as you kiss someone who is awake, lingering over his closed lips, compressing them as if to leave a mark. He gave a start, but didn't open his eyes. He parted his lips and went along with her. He was awake.

It was different from the first time. Their facial muscles were stronger now, more conscious, and they sought an aggression having to do with the precise roles of a man and a woman. Alice stayed bent over him, without getting onto the sofa, as if she had forgotten the rest of her own body.

The kiss lasted a long time, whole minutes, long enough for reality to find a fissure between their clamped mouths and slip inside, forcing them both to analyze what was happening.

They pulled apart. Mattia gave a quick smile, automatically, and Alice brought a finger to her damp lips, as if to make sure it had really happened. There was a decision to be made and it had to be made without speaking. They looked at each other, but they had already lost their synchronicity and their eyes didn't meet.

Mattia stood up, uncertainly.

"I'll just go…" he said, pointing to the corridor.

"Sure. At the end of the hall."

He left the room. He still had his shoes on and the sound of his footsteps seemed to be slipping away underground.

He locked himself in the bathroom and rested his hands on the sink. He felt stunned, groggy. He noticed a little swelling that was spreading slowly where he had hit his head.

He turned on the tap and put his wrists under the cold water, as his father had done when he wanted to stanch the blood gushing from Mattia's hands. He looked at the water and thought about Michela, as he did every time. It was a painless thought, like thinking about going to sleep or breathing. His sister had slipped into the current, dissolved slowly in the river, and through the river she had come back inside him. Her molecules were scattered all through his body.

He felt his circulation returning. Now he had to think, about that kiss and about what it was that he had come in search of after all that time. About why he had been prepared to receive Alice's lips and about why he had then felt the need to pull away and hide in here.

She was in the other room waiting for him. Separating them were two layers of brick, a few inches of plaster, and nine years of silence.

The truth was that once again she had acted in his place, had forced him to come back when he himself had always yearned to do it. She had written him a note and had said come here and he had jumped up like a spring. One letter had brought them together just as another had separated them.

Mattia knew what needed to be done. He had to get out of there and sit back down on that sofa, he had to take her hand and tell her I shouldn't have left. He had to kiss her once more and then again, until they were so used to that gesture that they couldn't do without it. It happened in films and it happened in reality, every day. People took what they wanted, they clutched at coincidences, the few there were, and made a life from them. He had either to tell Alice I'm here, or leave, take the first plane and disappear again, go back to the place where he had been hanging for all those years.

By now he had learned. Choices are made in brief seconds and paid for in the time that remains. It had happened with Michela and then with Alice and again now. He recognized them this time: those seconds were there, and he would never make a mistake again.

He closed his fingers around the jet of water. He caught some of it in his hands and bathed his face. Without looking, still bent over the basin, he stretched out an arm to take a towel. He rubbed it over his face and then pulled away. In the mirror he saw a darker patch on the other side. He turned it around. It was the embroidered initials FR, placed a few centimeters away from the corner, in a symmetrical position in respect to the bisecting line.

Mattia turned around and found another, identical towel. At the same point the letters ADR were sewn.

He looked around more carefully. In the water-stained glass there was a single toothbrush and next to it a basket of things all jumbled together: creams, a red rubber band, a hairbrush with hairs attached to it, and a pair of nail scissors. On the shelf under the mirror lay a razor, with tiny fragments of dark hair still trapped beneath the blade.

There had been a time when, sitting on the bed with Alice, he could scan her room with his eyes, identify something on a shelf and say to himself I bought that for her. Those gifts were there to bear witness to a journey, like little flags attached to stages of a voyage. They marked out the rhythm of Christmases and birthdays. Some he could still remember: the first Counting Crows record; a Galilean thermometer, with its different-colored bulbs floating in a transparent liquid; and a book on the history of mathematics that Alice had received with a snort but had actually read in the end. She preserved them carefully, finding an obvious position for them, so that it would be clear to him that she always had them before her eyes. Mattia knew it. He knew all that, but he couldn't move from where he was. As if, in yielding to Alice's call, he might find himself in a trap, drown in it, and be lost forever. He stayed there, impassive and silent, waiting until it was too late.

Around him now there was not a single object that he recognized. He looked at his own reflection in the mirror, his tousled hair, his shirt collar slightly askew, and it was then that he understood. In that bathroom, in that house as in his parents' house, in all those places, there was no longer anything of him.

He remained motionless, getting used to the decision he had made, until he felt that the seconds were over. He carefully folded the towel and with the back of his hand he wiped away the little drops that he had left on the edge of the sink.

He left the bathroom and walked down the hall. He stopped in the doorway of the living room.

"I have to go now," he said.

"Yes," replied Alice, as if she had prepared herself to say it.

The cushions were back in their place on the sofa and a big lamp lit everything from the middle of the ceiling. No trace of conspiracy remained. The tea had grown cold on the coffee table and a dark and sugary sediment had settled at the bottom of the cup. Mattia thought that it was merely someone else's house.

They walked to the door together. He touched Alice's hand with his as he passed close to her.

"The card you sent me," he said. "There was something you wanted to tell me."

Alice smiled.

"It was nothing."

"Before you said it was important."

"No. It wasn't."

"Was it something to do with me?"

She hesitated for a moment.

"No," she said. "Just with me."

Mattia nodded. He thought of a potential that had been exhausted, the invisible vector lines that had previously united them through the air and had now ceased to exist.

"Bye, then," said Alice.

The light was all inside and the darkness all outside. Mattia replied with a wave of his hand. Before going back in, she saw once again the dark circle drawn on his palm, like a mysterious and indelible symbol, irreparably closed.

The plane traveled in the dead of night and the few insomniacs who noticed it from the ground saw nothing but a little collection of intermittent lights, like a wandering constellation against the fixed black sky. Not one of them lifted a hand to wave to him, because that's something only children do.