Mark bolted up awake to the sound of retching. He looked beside him, at his wife fast asleep. There it was again -- it was the two-year-old.

Pushed by adrenaline, Mark staggered down the hallway in the dark, bumping the walls, falling forward. He had to move fast before the seven-year-old woke up. Then retching again, and sputtering.

He entered the baby's room and the stench hit him, the tangy choke of mucus and sour milk. Sitting up in the crib, chin and pajamas soaked with vomit, the little one looked surprised to see him but then raised his arms to be held.

A quick bath and two pairs of clean pajamas later, Mark carried the baby in one arm while changing the sheets with the other, bouncing him gently while quietly singing a just-remembered 80s classic. Welcome to your life, there's no turning back. The baby pulled back and looked at him, as if confused by the 3 a.m. playlist. "Give me a break," Mark said to the boy, "This time of night, you get what you get." Mark laughed. With this he felt lighter somehow, half-asleep but wide awake, refreshed at 3 a.m. And then he realized: the adrenaline rush of the last two years, the panic of midnight feedings and baby-proofing the house, was gone. Lost in the darkness. For once they were alone, just him and his son. Mark smiled at his boy. And the boy smiled back.

Mark carried the toddler through the dark house, whispering their song softly as the child listened. They saw the kitchen, strange and small in the darkness. The man in the refrigerator, whose drone had soothed the boy to sleep so many nights when he was an infant, hummed faithfully. As if remembering a shared, forgotten dream, they listened closely for a long moment.

They whispered their way down the hall, to the baby's mother sleeping in the big bed. The little one stared at her, stunned to see this all-powerful creature so small and helpless and vulnerable in sleep. He looked to his father and Mark nodded reassuringly.

Then down the hallway, to the seven-year-old's room. Legos on the floor, scattered checkers, and dirty clothes. In the bed, feet on the pillow and arms splayed here and there. The baby called out to his brother but Mark whispered to him, pulling him once again under his quiet spell. The older boy slept soundly, shadows from a streetlight outside shifting across him as trees waved in the breeze. They tiptoed closer to the bed and this time the baby whispered goodnight to his brother. The seven-year-old looked older and longer to Mark than before, and it occurred to him that the boy was in fact older than he had ever been. A new record destined to be broken tomorrow morning, then again every morning after that. The baby seemed to realize this too and looked at Mark. "Yeah, that's your big brother," Mark whispered. The baby's brow tightened. "It's okay," Mark smiled. "He's one of us."

They yawned back to the baby's room, back to the crib as tired eyes grew heavier. Mark squeezed the baby gently and whispered their song in the darkness. Nothing ever lasts forever. The baby pulled back and looked at his father again. Now a wise, ancient spirit, the baby held his father's gaze. They recognized themselves in each other's sleepy eyes and time slowed to a stop in the silence. Mark felt something inside himself float out -- he couldn't say what it was, but he felt it -- and it passed across into his little boy. Mark looked at his son, looking through dreams across time and into his own eyes. But more than that, he saw in his son's eyes the eyes of his own father. He and his son were the same, he knew now, the same body, the same mind, the same person, just 34 years apart. Just as he himself was merely his own father, just 30-some-odd years behind. The three of them were one, and where the piece of himself had floated out, Mark felt it was complete again, filled now with a piece of his own father. As Mark realized this and dried his eyes, the baby did as well, and his gaze became one of understanding. Of resolution. This moment -- this was what was real and eternal and permanent; time itself was the illusion. His eyes barely open now, the two-year-old looked at Mark, at himself in 30-some-odd years, and understood. The boy understood.

And then he puked all over Mark and that last pair of clean pajamas.