"We need a Christmas tree," Castiel says at breakfast on December 1st.

Martha perks up immediately. "I think that's a great idea! A nice proper tree for our first Christmas in the house."

Sam and Dean glance at each other; they don't exactly have the best track record with Christmas. But Castiel seems determined to experience everything humanity has to offer, and Martha's enthusiasm is hard to ignore.

Of course, they don't have anything to decorate the tree with either, so Sam and Martha end up picking up lights and ornaments while Cas and Dean get a tree. Because god forbid Dean do anything as unmanly as purchase pretty things when he could be wielding an ax.

Fortunately, Martha had a perfectly normal childhood and knows things about Christmas trees, like how much tinsel you actually need and how long the strands of light should be. They aren't exactly sticking to any kind of theme. The lights are multicolored, the ornaments in all shapes and shades. The only real issue is what should go on top of the tree.

Sam reaches for an angel without a thought; that's what you put on top of a Christmas tree, right? But when he turns to put it in the cart, he sees Martha going to pick up a star.

"You sure that's the best idea?" she asks, looking back at him.

"It's traditional," Sam says.

"My own personal issues with angel ornamentation aside, don't you think it might be a little weird for Cas?"

Okay, he's going to have to ask about that later, because that just sounds bizarre. Martha may have a point though. Sam can already almost hear Castiel asking why humans are so insistent about their ideas of angels in robes and pure white wings.

"But angels are so central to the Christmas story," he protests, not entirely sure why he can't let this go. But it seems important.

"Yeah, and you've met Gabriel," Martha counters. "How can you possibly take anything he's been involved in seriously?"

It does raise a lot of questions.

"We'll get the star," Sam concedes.

When they get home, they find a tree already set up in the living room. Sam notices the side facing the wall looks a little crushed, and the lamp that usually stands next to the sofa is suspiciously missing. Still, the tree is standing, and Castiel looks so proud. He doesn't mention it.

Much like shopping for ornaments, decorating the tree goes swimmingly until it's time to put the star on top. The tree is just barely too tall for Sam to reach up easily, and it would be too simple for them to own a step stool or something.

"Okay, so if I get on your shoulders, this should be doable," Martha says, tapping her chin with her fingers as she considers the tree.

It takes some finagling. Eventually, they decide the best way to do this is for Sam to get on his knees so Martha can use the couch to clamber onto his shoulders. She wobbles dramatically when Sam stands, and for a moment it looks like they might topple over. Sam steadies himself, wrapping his hands around Martha's thighs to keep her up.

"Okay, pass me the star, Cas," Martha says.

Castiel looks around, confused. "I don't have it."

Sam's pretty sure Martha is gearing up to say some choice things when Dean swans into the room.

"I had to fix it," he says, holding out the star and looking unnecessarily smug.

Taped to the star is a picture of Castiel. Sam's not even sure when anyone took a picture of Castiel.

"You gotta put an angel on top of the tree."