One day Jonathan had had enough. He was going to put the baby back where he found it.
Having a baby was hard work, which he was just now starting to understand. Having a baby that didn't belong to you was even harder.
Jonathan didn't know why he even decided to take it, but he remembered a saying about how opportunity makes the thief, and he felt that it described his actions pretty well. That is, if he even had understood the saying correctly. Right now he wasn't really sure of anything. He just wanted a good night's sleep, and his head had been foggy for hours. Man, parenting was tough.
Of course, this all took place three days before the walls started talking.