Isaac didn’t make mistakes. He was a very thorough and hard worker, and had been praised for that by his supervisor on so many occasions that he’d lost count, and something had to happen very many times before Isaac lost count of it.

He’d made a mistake today, though, and the part of the computer that checked his work for mistakes told him of his error with a box with a message in it saying that he needed to check again. After that he took his break (the one he was supposed to take twice every day, even though he usually didn’t and just said that he had) and went to stand in the bathroom with the light off and the rattling old duct fan on for exactly ten minutes. When he had counted six hundred seconds, he turned on the light again and took two pieces of paper out of his wallet.

One was a picture of Saturn, its rings, and two of its moons; that picture had arrived on earth on November 3, 1980, exactly six years, four months, and three days before Isaac was born, though it had been taken by the Voyager 1 spacecraft before that, because light took time to travel no matter where in the universe you were (at least on the scale at which humans and spacecraft operated).

The other was a list of things from Dr. Mazzy that were okay, and the third thing on the list was ‘making mistakes’. He read the whole list over four times, focusing on those two words in particular. He didn’t forget things; sometimes he just didn’t remember to remember them.

He decided it was okay to make a mistake when he was excited, and he was excited. On Friday, Rick would be back. That made thinking about anything else difficult.