Ruby Cantrell had walked out of Cumberland Ridge High School in March of 1958, and she still had the algebra book. It sat on the shelf above her flour bin for sixty-nine years, green cloth cover, her maiden name written inside in a careful sixteen-year-old hand. Ruby Mae Lawson, Room 12.
She'd never meant to keep it. She'd meant to bring it back.
Her daddy died on a Tuesday that March, out in the milk barn, with his hand still on the cow. The doctor said it was his heart.
Ruby was the oldest of five, her mother had a baby on her hip, and there were thirty-one Jerseys that didn't care who had died. They needed milking at five in the morning and five at night.
So Ruby milked them. She told herself she'd go back in the fall, and then in the spring, and then she married Carl Cantrell and had babies of her own, and the book stayed on the shelf.
Later she went to work in the cafeteria at Cumberland Ridge High, the same school she'd left. She cooked there for thirty years. She fed four hundred children a day, and she did it without a single recipe card, because she could take a pot of chili meant for forty and make it feed four hundred in her head.
Carl had been gone eleven years now. Ruby was eighty-five. Her knees were bad and her eyes were good, and on weekday afternoons she had company.
Her great-granddaughter Kenzie came off the school bus at Ruby's mailbox at 3:40 every afternoon, because Kenzie's mother worked the evening shift at the hospital in Morristown. Kenzie was seventeen and a senior, with long legs and a phone that never left her hand. Ruby loved her past all reason.
On the second Monday in February, Kenzie came through the kitchen door and threw her backpack at the floor so hard it slid under the table.
"I'm done," she said.
Ruby kept rolling biscuit dough. "Done with what, honey?"
"Algebra Two. Mr. Odell says if I fail the final, I don't graduate. I've got a forty-eight in there, Mamaw. A forty-eight." Kenzie dropped into a chair. "And I'm never going to use it. Not one time in my whole life."
Ruby cut six biscuits with a jelly glass and set them on the pan. Then she wiped her hands, dragged the step stool over to the shelf above the flour bin, and climbed up. Kenzie said, "Mamaw, don't you dare climb that," and Ruby climbed it anyway and came down with the green book.
She set it on the table between them.
Kenzie turned it over. "What's this?"
"My algebra book. Nineteen fifty-eight."
"You took algebra?"
"I took half of it." Ruby sat down. Her knees complained about the stool. "I quit school in March of my sophomore year. Daddy died, and the cows needed me more than Mr. Hensley did."
Kenzie looked at her for a long moment. She'd heard the story about the cows. She hadn't put it together with this.
"So you never finished," she said.
"No."
"And you were fine. You had a whole life."
"I had a good life," Ruby said. "I'd have still had it with a diploma. I used to stand behind that steam table and watch those children go by in their caps and gowns every May, and smile at them, and go home and not tell Carl why I was quiet." She tapped the book. "You think you'll never use it. I used it every day for thirty years. I just never got to write it down on a test."
Kenzie flipped the book open. Ruby's sixteen-year-old pencil marks were still in the margins of Chapter Six.
"Okay," Kenzie said slowly. "Then here's the deal."
"I'm listening."
"If I have to pass algebra, you have to pass it too. You go get your diploma. The equivalency test thing. And we study together, right here, every day." She crossed her arms. "If you quit, I quit."
Ruby should have said she was too old. She should have said her eyes got tired after supper and her hands shook a little holding a pencil.
What she said was, "When do we start?"
They started that Wednesday.
The county adult education office was in the old bank building on Depot Street, and the woman at the front desk didn't blink when an eighty-five-year-old walked in to sign up. She gave Ruby a practice booklet for the HiSET, the state's high school equivalency test.
Five sections. Reading, writing, science, social studies, and math.
Ruby breezed through the reading. She'd read the Bible cover to cover nine times and every Louis L'Amour in the county library. Science and social studies came back to her like old hymns.
Math sat on her chest like a cow lying down.
Kenzie taught her the calculator they'd let her use, a gray thing with more buttons than a church organ. Ruby taught Kenzie something too, though neither of them knew it at first. When Kenzie got stuck on a word problem about a train and a truck, Ruby said, "That's just feeding a crowd. You know what one plate takes. You need to know what four hundred takes." And Kenzie stared at her, and then at the paper, and wrote the equation down.
By April, Kenzie's grade had climbed to a sixty-eight. Ruby was scoring well on every practice test but one.
She took the real HiSET on the third Saturday of April, in a small room above the old bank, with three young men in work boots and a girl who looked about Kenzie's age. Ruby wore her church dress. She sharpened two pencils at home, though they gave her new ones.
The scores came four days later. Kenzie read them off her phone at the kitchen table, standing up, one hand pressed flat on the oilcloth.
Reading, passed. Writing, passed.
Science, passed. Social studies, passed.
Then Kenzie stopped reading out loud.
"Math," Ruby said.
"You needed an eight." Kenzie's voice went small. "You got a six, Mamaw."
Two points. Ruby had missed her diploma by two points, sixty-nine years after she'd walked away from it.
"Well," Ruby said. "I'll take it again."
Kenzie was already scrolling. Her face fell further. "The next test date at the county office is June twelfth."
Cumberland Ridge High School's graduation was May twenty-first.
Ruby had passed every section but math, by two points, and the next test date was after her great-granddaughter's graduation.