“Mama, please.”
“Who is she?” Mama asked.
“No one!”
“She isn’t no one. What’s her name?”
“Angela, but she’s just a friend. She and Papa go to art fairs together.”
“They . . . go to art fairs together,” Mama repeated.
“Not like on dates or anything. They’re just always at the same fairs at the same time!”
“I see,” Mama said faintly.
“Ava?” Papa called from the kitchen.
“One sec!” Ava called. Should she pull Mama into the house? Should she physically grab her and hold on to her?
Mama thrust the brownies at her, and then she was gone, the screen door thumping behind her.
Ava heard Papa’s heavy footsteps. She pivoted away from the back door.
“Ava,” Papa said. “I came to check on you, because you seemed . . .” He rubbed the back of his neck. “Are you upset about something, honey?”
Ava shook her head.
He put his hand on her shoulder. “I know—well, or maybe I don’t. I don’t want to put words in your mouth.” The weight of his love made her want to cry. “But it can be confusing to be a teenager. And with your mother gone . . .”
She’s not gone! Ava wanted to say. She was just here!
“Do you like Angela, sweetheart?” Papa asked, and his vulnerability broke Ava’s heart. He was moving on. He was finding happiness again. What was Ava supposed to do? Stomp her feet and throw a fit? Tell him she didn’t like Angela, even though she probably secretly did, or could, if it weren’t for everything else going on?
“Here,” Ava said, handing him the plate of brownies. Her voice hitched. “For dessert.”
Papa’s face lit up. “Brownies!” He raised his voice. “Ava made brownies, everyone!”
“Oh, wonderful!” Angela caroled.
“You’re a good kid, Ava,” Papa said, shifting the brownies to one hand and giving Ava a one-armed hug.
“You’re a good papa, Papa,” Ava whispered, wrapping her arms around his waist and pressing her face to his shirt. He gave her one more squeeze before heading back to the dining room.
“You coming?” he said, glancing over his shoulder.
She forced herself to smile. “Be right there.”
CHAPTER THREE
Ava
That night, after Angela left, Ava got to the den first and claimed the TV. She used the remote to scroll through menus and punch in selections, and within minutes, the movie she’d picked was playing.
“Back to the Future?” Stanley said half an hour later, following Natasha into the room. He must have come over after dinner. He dropped onto the other end of the sofa, and after a moment, Natasha sat down between them.
“I watched this three times in a row the first time I saw it,” Stanley said. “Can we join you?”
“You already have,” Ava pointed out.
“Oh,” said Stanley. “True. Do you want us to leave?”
“It’s fine,” she said. Ava liked Stanley. He was tall and lanky and shy, though he’d grown less so over time. Most importantly, he treated Natasha well.
“Awesome,” he said, and right away started reciting lines along with the characters. When Doc Brown showed up in his DeLorean, he laughed and said, “Yes.”
Ava wondered if DeLoreans existed in real life—sleek, sporty cars with doors that opened up instead of out. She’d never seen one. She’d remember if she had.
“Gull wings,” Stanley said.
“Huh?” said Ava.
“The doors. They’re called that because they resemble the wings of a gull.”
“Huh,” said Ava.
“It makes the car more streamlined. Better for time travel.”
“Ah. Well, of course,” Ava said. She and Natasha shared an amused glance. Still, Ava made a mental note: Streamlined. Okay.
“Do you know why else Doc built his time machine using a DeLorean?” Stanley asked.
“Please tell us,” Natasha teased.
“For a couple of reasons. First, the DeLorean is constructed from stainless steel. That was crucial in terms of creating the flux capacitor.”
Ava perked up. She knew that the flux capacitor was the Important Thing that allowed Doc Brown and Marty McFly to go back in time, but that was all she knew. Stanley kept talking, using terms like “rear-mounted two-point-eight-five-liter blah-blah-PRV engine,” “fiberglass body structure,” and, bewilderingly, “a steel backbone.”
“Do you know why Doc was so particular about every detail?” Stanley asked.
“Because he wanted to get it right?” Ava guessed.
“To increase his chances of having a smooth passage through the space-time continuum,” said Stanley.
Ava sat up straighter. After her epiphany beneath the willow tree, she’d stopped by the public library and pored over scientific articles exploring the possibility of time travel. Gravitational field equations, something called Tensor Calculus, Einstein’s theory of general relativity . . .
The reading had been dense and had made her brain hurt. She’d decided to watch Back to the Future in the hopes of finding an easier way to unravel the mysteries of time travel. She knew it was just a movie, but still.
On the television screen, Marty McFly was having a soda with George McFly, who would one day be Marty’s father—unless Marty screwed things up.
“Do physicists really believe in that thing you just said?” Ava concentrated on getting the term right. “Space-time continuums?”
Stanley grinned. “Sure they do. So do I, and I’m not even a physicist.”
“And the concept of a space-time continuum means thinking of the world not as three-dimensional, but as four-dimensional,” Ava said, furrowing her brow. “Is that right?”
Natasha gave her a funny look.
“That’s a simplified way of describing it, but yeah,” Stanley said. “We exist in space. Space is three-dimensional, with height, width, and depth.”
“Unlike a painting, which is two-dimensional,” Ava said.
“Actually, a painting is still three-dimensional. You can hold a painting, right? Like if you were hanging it on the wall?”
“Well, yeah.”
“But the image represented in the painting is two-dimensional. If it’s a painting of a bridge, for example—”
“The bridge in the painting is two-dimensional,” Ava said. “Got it. And since I’m three-dimensional, I couldn’t walk over the bridge, even if it were life-size.”
“Guys? The movie?” said Natasha.
Ava scooted forward on the sofa, leaning past Natasha to better see Stanley. “But time is different. It’s not height or width or depth. That’s why it’s called the fourth dimension?”
“It’s more complicated than that, but that’s a decent starting point,” Stanley said. “You, Ava, are
