Although Sam was extremely tired, his fear kept waking him up every hour or so. When two hours had passed, he finally gave up. His body wasn't going to let him sleep any more. He kicked off the covers and stood up, taking the pull up off and getting redressed before searching for Ellen and Jo. He found Ellen in Dean's room, changing him into a fresh diaper. Being a mother, her instincts were sharp as a tack. She sensed Sam there before he even made a peep.
"Can you hand me the baby powder, Sam?"
He blinked. How did she know he was here? He shook his head and handed it to her.
"Thank you."
She finished diapering a still sleepy looking Dean, then gave him some Tylenol, just to make sure his fever stayed low. When that was done, she led both boys back out to the front of the roadhouse. Dean planted himself on the floor, cuddling with his blanket while Sam looked up at Ellen expectantly.
"Do you want to have your snack now, Sam?" She asked. He nodded and she handed him his carrots and juice. Dean never said a word about wanting anything to eat. He just sat there, perfectly still. Sam started eating, but Dean made a face and turned away. The idea of food wasn't appealing right now.
He looked over at where his bag was and went over to it, wondering what Daddy left him. There were two of his favorite books and a recorder. Cas had made a tape of himself reading the books so that Dean could hear his voice. He had packed his favorite toy Impala, a few liked action figures, and an iPod full of songs that made Dean feel happy. Last but not least was his pacifier. He smiled and popped it into his mouth, then plugged the headphones from the iPod into the recorder and pressed play, following along with the book. When that was over, he turned back to Sam, but smelt his food. His stomach roiled in the worst way and he spat his pacifier out. He ran to the trash can and threw up.
Ellen was there instantly to help hold him up. He was so weak that he could barely stand up. She rubbed his back and hushed him while he cried, frightened. He was like that for twenty minutes, confused and frightened. When he was sure it was over, he curled up on the floor with his blanket. Ellen stayed with him while Jo tried to entertain Sam. He was just as worried about his brother as anyone else was and refused to leave his sight. Ellen left briefly to take his temperature and saw his fever spike. Dean shivered under his blanket and whimpered quietly. What was wrong with him? He didn't have much time to ponder the question. A haze of confusion entered his brain. He was suddenly quiet and still. He grunted, and then the seizure began. His body began to jerk uncontrollably and his head kept hitting the floor. Ellen grabbed his blanket and put it under his head to cushion the blow, and turned him onto his side. Sam started trying to get to his brother, but Jo held him back. She knew he could get hurt. When the seizure slowed two minutes later, Jo let a crying Sam go sit with his brother.
It took a minute or so more for the seizure to stop completely. Dean was still completely unaware of his surroundings. Sam and Jo both looked worried, but Ellen looked as if she'd had an epiphany. She had Jo take her place by Dean and quickly ran to the computer. She had a hunch about what was really ailing Dean. She put in all of his symptoms and it came back a perfect match. It wasn't a cold or flu ailing him.
It was Low blood sodium.
It caused fevers, weakness, fatigue, confusion, irritability, seizures, and headaches.
Now that she knew, she wrote down how to cure it before going back out to everyone else. Dean was still staring glassy-eyed at the wall. Sam kept tapping his shoulder, telling him to wake up. Tears were in his eyes, and Ellen felt pity well up inside of her for him. Dean finally started moving after fifteen more minutes. He was confused and felt like a bog had entered his brain. But he responded to their questions appropriately, so that was a relief.
It was about a half an hour after that that Castiel and Gabriel returned for their children. Castiel saw Dean staring at him sleepily and smiled before gently picking him up.
"He was a very sick little boy today." Said Ellen. "He threw up a few times and had a seizure while you were gone, but I think I finally pinpointed what was wrong with him." She handed him the paper on low blood sodium. It all made perfect sense. Castiel pressed two fingers to Dean's forehead and searched for the ailment. To his absolute relief, he found it and was able to cure it. Instantly, Dean was back to his regular self, and Castiel silently thanked his father for that.
"Thank you so much for helping." Castiel said gratefully. "Are you coming with us?"
"You bet." Said Jo, grabbing her purse. Dean and Sam both looked up at Castiel curiously.
"Where are we going, Daddy?" Dean asked sweetly.
"You'll see." He promised, ruffling Dean's hair. He and Gabriel shared a look and nodded to one another before putting a hand on Ellen and Jo and disappearing. They rematerialized outside the cabin, and both boys looked at him curiously. Castiel opened the front door and walked inside the darkened place. He waited for everyone else to come in and the door behind him to shut before flipping on the light switch.
Then, at least half a dozen people jumped out of hiding places and all shouted,
"SURPRISE! Happy Birthday, Dean!"