You would not believe your eyes, if ten million fireflies, lit up the world as I fell asleep…

It was another ordinary summer day—well, ordinary for Dean and Sam Winchester, anyway. Their father was away on a hunt, as per the norm, and the young boys were staying in a hotel, again, as per the norm. Since it was summer and they didn't have school to attend, Dean was letting his little brother stay up late. But it was after nine, which was almost too late for Dean to keep his eyes open and definitely too late for Sammy.

"Come on, Sam," Dean wheedled, "it's time to go to sleep."

"But Dean!" the excited six-year-old said. He had his head ducked through a small opening in the curtains that covered the one window in the motel, staring out into the parking lot. "You have to look at this!"

Dean yawned, then sighed. "Fine. But then will you go to sleep?" At Sam's vigorous nodding, Dean made his way over to the window. Sam stepped aside, his small face lit up with excitement, and Dean poked his head through the opening in the window. "Whoa."

The motel parking lot was filled with lightning bugs, all with their lights flickering on and off in a steady rhythm.

"Do you see all the fireflies?" Sam asked, still excited. "There's gotta be ten million out there! Dean, can we go out and try to catch some? Please? We never get to catch fireflies!"

And Dean turned to face his little brother, turned to tell him that no, they can't do that, because Dad said not to leave the motel and besides, that many fireflies in a parking lot can't be normal, but one look at his little brother's hopeful face and he changed his mind. Dad wouldn't have to know and besides, they never do get to catch fireflies. Not even once.

"Okay, Sammy," Dean relented. "But only for a little bit. And you can't tell Dad."

"Yay!" Sam cheered. "You're the best big brother EVER!" He was jumping up and down in place, like a little jumping bean, and Dean grinned at him.

"Yeah, yeah, I am pretty great. We're gonna need a jar for all these fireflies we're gonna get."

After much searching, the boys tracked down a pickle jar to capture the bugs in. Dean washed it out, and then stuck the key to the room carefully in his pocket. Sam was waiting for him at the door, bouncing in place again and oozing with excess energy. "Are we ready to go now? Can I hold the jar? Can I hold a firefly? Are we gonna let them go again after we catch them? If we aren't, can I use them as a nightlight?"

"Yeah, yeah, yeah, and we have to let them go or they'll die," Dean told him. Sam looked slightly disappointed about not getting a new nightlight, but held his hands out for the jar, which his brother placed in his hands. For a while, they ran around, catching fireflies like normal kids. And after a while, they got tired like normal kids, and lay down in the grass next to the parking lot, watching the stars and the lightning bugs.

"It's time to let them go, Sammy," Dean said when he was sure it had to be after ten.

Sam gave him a pleading look. "Please can't we keep them? Just for one night?" But Dean shook his head.

"They have to go home. To their families. Here," he said, and handed his little brother the glowing jar again. "You can let them go."

Sam took the jar, and his face was illuminated by it when he smiled up at his older brother.. "Thanks, Dean."

"For what?" he asked.

"For the best night ever," Sam said earnestly, and Dean grinned at him as he turned and ran out to the middle of the parking lot. He saw Sam twist the jar open and the fireflies flew out, and then—

There was a man there, right in front of Sam, and he had just appeared out of nothing. Dean gasped and yelled Sam's name as he ran towards him, saw the man look at him with eerie yellow eyes, saw Sam frozen in place with fear, kept running and was almost there when the man raised his hand and it felt like he ran into a brick wall, only there was nothing there.

"Oomph!" Dean grunted as he was knocked to the ground and the wind was knocked out of him. When he pulled himself to his feet, the man was gone, and so was Sammy. The only signs of life were the fireflies, with their lights still steadily blinking on and off. But even they were beginning to disperse now.

"Sammy!" Dean yelled, running to the spot where his little brother had been. The jar was broken, smashed to bits on the asphalt. "Sam!" He whirled around, hoping that maybe Sammy would be behind him, and that he had just imagined the man, but…

No.

Sam was gone. Dean didn't know where he had been taken to, but he knew the yellow eyes. The thing that killed his mom. It had taken his mom from him, and he didn't know why, but now it had taken Sammy. And as the last of the fireflies left the parking lot, ten-year-old Dean Winchester sank to his knees, put his head in his hands, and began to sob.