They're in a garden of some sorts with a old fashioned house in the background.
"This is Heaven?" Sam asks a bit disappointed because it looks pretty much like Earth but then he remembers that Heaven is all about memory and these are Gabriel's. Gabriel rolls his eyes:
"It's my memories interpreted by your human mind because anything else would burn your pretty eyes out."
Sam's attention turns to the garden again. A teenage boy sits on a chair in a sunny spot with his blond hair neatly combed. He's reading and doesn't notice the two boys in the tree above him. The older one is also blond while the younger is a redhead.
"Is that you?" Sam asks, gesturing at the redhead. Gabriel nods.
"And the other one is..." Sam trails off because he has a fairly good idea who the blond boy next to Gabriel is.
Gabriel and Lucifer are trying so hard not to laugh that their faces are red from the effort. Finally they reach the end of the branch directly over Michael and drop whatever they were holding in their hands.
Two seconds later Michael is red and yellow and green and Gabriel and Lucifer look like they're about to fall out of the tree.
"Lucifer! Gabriel!" Michael bellows but they're already gone.
It's the garden again but this time it's night.
"Michael said!" Gabriel protests but Lucifer rolled his eyes at him:
"Michael always says something. Nobody died and made him dad. And Dad didn't forbid us going to Earth did he?"
"Oh, come on! It was your idea to make giant lizards." Lucifer reminds him impatiently and tugs at Gabriel's hand.
"Dinos!" Gabriel corrects him: "I'll call them Dinos!"
"You wanna make Dinos or not?" Lucifer asks again and his mischievous grin is a promise of adventure and fun.
"Okay." Gabriel gives in but Sam can hear him mutter behind Lucifer's back:
"But if we're grounded I'm blaming it all on you."
It's Gabriel and Lucifer again in the garden on their tree but this time they're not alone. Sam can see a lot of other children hiding between trees, bushes and stones because they're apparently playing hide and seek. The little girl that has to find the others reminds of Anna a lot so it's probably her. She has caught a little black boy, Uriel?, who's pouting.
"Got you!" Anna yells at Lucifer but Lucifer vanishes under her fingertips.
"You're cheating!" She yells before she storms off to find someone else.
"I didn't know you could do that!" Gabriel admires his older brother. Lucifer shrugs as if it's nothing.
"You can do it, too." He tells Gabriel: "Just imagine you're down there."
"No, no." Lucifer laughs and grabs Gabriel's hand to stop him from flying off:
And Gabriel does.
Someone steps out on the porch that Sam can't see but he's taller than everyone else even Michael.
"Is that God?" Sam asks with a tight throat but Gabriel merely nods and keeps his eyes on the scene in front of them:
"It's our new brother." Michael announces in a very serious tone but even he can't keep from smiling at the small bundle in God's arms.
"Can I hold him?" Gabriel asks impatiently and stretches his arms out. God gives the bundle to him and Lucifer asks:
"Can I name him?" Only a second later Michael announces again:
"His name is Castiel." Lucifer pouts and throws his older brother a deathly glare. Anna tugs at Gabriel's arm, trying to balance on her toes to see her little brother:
"Can I see him? Can I see him?" Gabriel very carefully shifts the bundle in his arms and Sam laughs because the baby has dark hair and big blue eyes. Anna laughs at him and babyCas laughs back. Lucifer touches babyCas' nose with one finger tip and babyCas wrinkles his face.
"No sense of humour." Lucifer declares but looks curiously down when Cas wraps his tiny hand around Lucifer's finger.
The five of them, Cas in Gabriel's arms, holding onto Lucifer with Anna on the tips of her toes and Michael leaning on Lucifer's shoulders they're the perfect image of a happy family.