Crunching a mouthful of cornflakes and milk, I watched the snow come down outside. Because of that snow I had a whole day off from school. Not much fun without anyone to spend it with, I thought as I poured myself another bowl of cereal.

Loud thumps on the stairs announced that my 15-year-old brother, David, was awake at last. David and I used to spend lots of time together zipping our toboggan down icy hills in winter or passing lazy summer days in the three-story treehouse that overlooked the creek. But now that he was 15, David had better things to do than hang out with his 10-year-old sister.

The cornflakes stuck in my throat as I remembered the last time I had gone to David's room for a chat. "Can't you see I'm on the phone?" he had yelled. "I shut the door so I wouldn't be bugged—by you!" I had backed out of the room, but not quite quick enough to miss hearing David tell his friend, "My little sister is a real pest."

The breakfast dishes rattled as David jumped down the last three steps and landed with a thud in the hallway. "Hey, Renea!" he called. "The guys and I are planning a snowball fight, and I need some target practice. Get your snowsuit on." I froze in mid-chew. David wants to play with me?

I jumped up and pulled on my coat and hat before he could change his mind. David wound a scarf around my neck. "Let's party," he said, giving me a wink. It felt like old times.

Outside we stumbled through piles of snow, our heads bent down against the wind. The snow came up almost to my waist and hit David right above his knees. He held my hand tightly so I wouldn't fall, the way he always had. When I learned to ride a two-wheeler, it was David who ran behind me steadying the back of the seat.

Now my big brother was already talking about going away to college. David was not scared of being on his own. He was not scared of anything. When I got frightened, he was always there to protect me. He won't be around much longer, I thought, gripping his hand tighter. Who will look out for me then?

Through the whirling snowflakes I recognized some girls from my class. David waved to some boys his own age. One of them tossed a well-packed snowball toward my friends. "Snowball fight!" someone shouted.

Before I could make my first snowball my brother dumped a handful of snow over my head, most of which slid down my neck, under my shirt and into my underwear. "Boys versus girls!" David said, grinning. "Let's go!" I scooped up a handful of snow and attacked.

It wasn't much of a fight. It was more like a shooting gallery with us girls as the little yellow ducks. Most of our snowballs plopped down into the snow right in front of us, not hitting the boys at all. Pretty soon I was soaked, but I didn't care. David and I were having fun. This was the best snow day of my life!

"Let's get some hot chocolate," one of the boys suggested. The teenagers walked off, leaving us girls behind. Just like always, I thought. Big brothers only care about you until something better comes along. I hurled a snowball at the retreating figures of the boys, but they didn't even notice it behind them.

"Hey, Renea, help us make a snowman," one of my friends called.

"No, thanks," I said, wrapping my scarf tighter. "I'm going home."

As I started back over the snow, something caught my eye. Across the field, beside the frozen creek, stood the empty treehouse. Its first two stories sat in the fork of the tree. But the third part of the clubhouse was on the very tallest branch, hanging out over the water. If I climb up to the top, David will have to come up to get me. That's when I'll hit him with a pile of snowballs from above! My plan was sure to work. I'd get my brother's attention.

I chuckled to myself as I made my way up the rope ladder that connected all three parts of the treehouse. On the top floor the wind was stronger. The ice-coated branches cracked, and the tree swayed beneath me as I packed my snowballs, one by one. The sun lit the frozen creek with a pinkish-orange glow.

"Renea!" David called out from across the field. "Get down from there right now!" His voice was sharp and had something in it I'd never heard before. Something almost like fear. David's afraid? A clump of snow fell from the branches above me and thumped down onto the wooden floor by my feet.

"David!" I called, suddenly afraid myself. I felt the floor beneath me shift. Then a loud crack split the air. Before I could even scream, the treehouse came crashing down. I plummeted straight down toward the frozen creek!