Ivy Blake drummed the eraser end of her pencil on page 162 of Science Grade 5. A spring breeze reached in the open kitchen window and patted at her face. Polar bears have no natural enemies, except humans, she read. She gazed at a photograph of two polar bears standing face-to-face in a snowfield, their arms stretched out to each other. The bigger one rested his paws on the little one’s waist; the little one’s paws were on the big one’s shoulders. He had one leg kicked out to the side like he’d just done step two of the box step, which Grammy had tried to teach her and Prairie last weekend.

Ivy turned the page. Polar bears depend on ice floes for their survival. They use them to hunt from, live on, and as a place to rest when swimming. The warming of Earth’s climate has caused these ice floes to thin and grow smaller.

In this picture a polar bear stood on an ice floe not much bigger than the front porch, staring at the mountain range that lay in the distance. Ivy put her fingertip on the bear’s nose, and then on his porch-sized ice floe. She had a feeling she knew how he felt.

“Ivy!” Prairie called from outside. She was jogging up the path from the barn. “I-vee!” She burst into the kitchen, smacking the door up against the inside wall. “What’re you doing?”

“Studying.”

“Still?”

Ivy made an apologetic face.

“But you studied at lunch and on the bus and before dinner. How can you stand to study any more? And anyway—” Prairie made a helpless gesture toward the outdoors. Ivy knew what she meant. You didn’t need a winter coat, finally.

But studying in the kitchen in the early evening was always one of her favorite parts of the day. The room wrapped itself around you like one of Mom Evers’s blankets. Along the walls, there were colorful wooden chairs that Dad Evers had repainted and quilts stacked in piles waiting to be sold at the farmers’ market. The windows were filled with plants and Dad Evers’s painted birdhouses, and a dusty catnip mouse lay abandoned by her cat, Pup, on the floor. Tonight Mom Evers was working at her sewing machine, Grammy was reading, and every now and then Dad Evers came in for a sheaf of stencils or a smaller paintbrush. It would’ve been perfect, the hum of the sewing machine the sound track to their quiet industry, except for Prairie. Her cheeks were red, her eyes sparked, she smelled like air and dirt.

“That test tomorrow is not going to be easy, you know,” Ivy said. “I just want to do well.”

“Well, okay, but can’t you take a break? Come outside, I’m making a goat pen.”

Ivy smiled at her best friend. Over the winter, Prairie had decided she wanted to raise goats, and she wasn’t the kind of person to wait around for the actual animal itself to show up to get started. “In a while, maybe.”

Prairie rolled her eyes. “You’re going to ace the test, anyway, you always do.” She banged back outside and Ivy went back to work. Polar bears show angry behavior when they lose their prey. They might kick snow or growl when they’re disappointed.

Grammy looked up from her reading. “You have hit those books a good long spell, Knasgowa.” Knasgowa meant heron, in Cherokee. Grammy was part Cherokee and she had started calling Ivy that over the winter. She called Prairie Tatsuwa sometimes. That meant raven. Other times she called her Saligugi, which meant snapping turtle, and anyone could see why.

Ivy smiled without looking up.

“There is such a thing as overdoing it.”

Ivy tipped her head. “But I have to know this stuff. There’s a test—”

“Prairie’s right, you know. You are going to ace it. You always do.”

“Because I study.”

Grammy rolled her eyes. “That you do. But you also overstudy.”

“That’s not even poss—”

“A person can overdo anything. It’s like exercising too hard. Does more harm than good. I’m not telling you what to do, mind you—”

Ivy made her face very polite but she couldn’t help the skeptical glint in her eyes.

Grammy laughed. “I’m just saying, I think you might’ve hit that magic point where you know the material and ought to just let it simmer away in your brain for a while.” She winked and returned to her book, and Ivy went back to hers.

Polar bears look white, but their fur is actually transparent. When light bounces off them, they appear to be the same color as the snow around them. They blend in easily with their Arctic environment.

Ivy drew a little polar bear at the bottom of her notebook page. She sketched an ice floe underneath it, then shaded in the surrounding open water with the side of her pencil lead. She made two mountain ranges out of the words May and June. May was close; June wasn’t very far behind it. June, when the school year ended. On the plus side: the school year ended. And she was going to North Carolina with Grammy and Prairie for a two-week vacation, which was pretty much the most exciting thing she’d ever dreamed of. On the minus side: the school year ended. And then what? What would her mom decide? Would Ivy have to move back in with her and George in Poughkeepsie? Did Ivy even, in a way that made no sense to her, sort of want to?

She studied her drawing, her lips pursed. Then she flopped her books shut and slid them into her backpack. She grabbed her jacket off the hook beside the door and went to find Prairie.

Once she was holding a splintery plank up against a post so Prairie could nail them together, she realized that the best part of her day had just changed, from studying in the kitchen, to this.