It was the first time they went to Uncle Bobby's that Dean realized Mommy was never coming back.
It had been all jumbled up in Dean's head before that, because Daddy told him that Mommy went to Heaven, and when people went to Heaven, they never came back. A long time ago, Mommy used to have a mommy and a daddy, but they went to Heaven and Dean never met them. Daddy had a mommy and a second daddy because his first one got lost and a little sister, and they were in a car wreck while Daddy was in the Marines and they went to Heaven. They never came back either.
But when Sammy was just born Dean got lost at the grocery store one day. Mommy found him crying at the front door because he thought she took Sammy home and left him there. Mommy had promised that she would never, ever leave him or Sammy anywhere and not come back.
Mommy wouldn't lie. She wouldn't leave her boys and go to Heaven forever. So Dean had been waiting for Mommy to come back.
Every time Daddy put them in the car and put all their things in the trunk and drove away from wherever they'd been staying, Dean always hoped they were going back to their house and Mommy was going to be waiting.
He learned not to ask Daddy though, because sometimes it made Daddy really angry when Dean asked if they were going to get Mommy now, but most of the time it made him very sad. One time he even pulled over, got in the back seat and put Dean and Sammy in his lap and cried. It scared Sammy and made him cry too.
Dean stopped asking if they were going to get Mommy now, but he still hoped.
On the second day at Uncle Bobby's house, Dean took Sammy upstairs and put him in the playpen, and then he came back down to ask Daddy if they could go outside. It was nice and sunny and the grass was probably dry now.
He heard Daddy and Uncle Bobby talking, and he heard Uncle Bobby tell Daddy to leave and go find a good job and a stable home. Dean was about to ask if they were going to live with horses because horses live in stables when he heard what Daddy said back to Uncle Bobby.
"They'll be a lot better when I find the thing that came after Sam and killed their mother."
That was the day it wasn't all jumbled any more. Dean went back upstairs without asking to go out because he knew Daddy would probably be mad if he asked right now.
Mommy was never coming back, because a monster got her.
And the monster wanted Sammy.
Dean went back upstairs, where Sammy laid in the playpen, chewing on a stuffed bunny. He stepped very carefully over the line of salt.
Daddy told him that salt keeps monsters away. Now Dean knows why the salt is important. It keeps the monsters from stealing Sammy.
Dean turned around, licked his finger, stuck it in the salt line, and then carefully climbed into the playpen. He stuck his finger in Sammy's mouth, and Sammy sucked on it. He made a face at the salt.
"I know, but you need it, Sammy." Dean whispered. "So the monsters won't get you. Monsters don't like salt. If you taste like salt, they'll spit you out."
From then on, Dean always put salt on Sammy's food. Sammy wouldn't eat it if there was a lot of salt, so Dean just had to add a little and hope it was enough. He didn't know how much salt it took to get rid of a monster.
But a few days later, he got another idea. He started putting salt in Sammy's bath water too, so Sammy's skin would taste like salt.
Maybe it would be enough to keep the monsters away.