The Map That Grows Its Own Roads

Deb ran ahead of them on the muddy trail, gray ponytail swinging, sixty-eight years old and not even breathing hard. Maya and Soren jogged behind, mostly failing.

"She's older than my grandmother," Maya said between breaths. "How is she beating us."

"Practice," said Soren. "She's run this loop every morning for forty years. She told me she still remembers the loop she ran when she was our age. Every turn."

Maya slowed to a walk. Soren stopped with her.

"That's the thing I don't get," she said. "My mom says her brain is full. She says she can't learn anyone's new phone number anymore. Like the brain fills up and stops."

"So how does Deb keep forty years of turns in there," Soren said.

"That's my point." Maya kicked a pinecone off the trail. "Either the brain fills up or it doesn't. It can't do both."

Deb had looped back to find them stopped. She ran in place, grinning.

"You two look like you're solving something," she said.

"Maya thinks brains fill up," said Soren.

"I did think that," Maya said. "Now I don't know what I think."

Deb laughed. "Ask me why I run," she said. "Everybody thinks it's for my knees or my heart. It's not." She tapped her temple. "It's for up here. After my husband passed, the doctor said the running would help more than any pill. I thought he was being nice. He wasn't. He was being a scientist."

Then she was gone again, up the trail.

Maya watched her go. "Why would running help your head," she said. "Your legs are nowhere near your head."

Soren pulled his notebook out of his jacket and wrote something while he walked. Maya didn't ask what.

"Okay," he said. "Say the brain doesn't fill up. Say it can make more room. Where would the room come from?"

"New parts," Maya said immediately. "You'd have to grow new parts."

Soren stopped walking. "That's not allowed, though. That's the whole thing everyone says. You're born with all your brain cells and then you only lose them. My dad says that every time he forgets his keys."

"Everyone said Deb's brain was full, too," Maya said. "And she remembers a loop from sixty years ago and learns new race routes every spring." She turned to face him. "What if the everyone is wrong."

They started walking again, faster now. "Here's how I'd test it," Soren said. "If the brain grew new cells, it wouldn't grow them just anywhere. It would need a place. A workshop. Somewhere memory gets made."

"Does it have one?"

"There's a part with a name I like," Soren said. "Hippocampus. It means seahorse, because of the shape. It's where new memories get built before they get filed away. Deb said turns. Directions. Maps." He looked up. "Maps are exactly what that part does."

Maya's eyes went bright. "So the seahorse builds the maps. And Deb has forty years of maps. So the seahorse would have to keep building." She grabbed his sleeve. "Soren. What if running is what tells it to build."

"Why running, though," he said. "That's the part I can't get. Legs are nowhere near the seahorse. You said it yourself."

They came around the bend and found Deb doing slow stretches by the water fountain, steam coming off her shoulders in the cold.

"Deb," Maya called. "When you run, what does your blood do?"

"Goes everywhere fast," Deb said. "That's rather the point of it."

"Everywhere," Soren repeated. "Including up."

And there it was. Maya watched it arrive on his face, and she felt it arrive on hers at the same time.

"The legs don't have to be near the seahorse," Maya said slowly. "The blood connects them. You run, the whole body floods, the head gets more of everything, and the seahorse gets the message. Build. Build. Build."

"That would mean the running isn't for the legs at all," Soren said. "Or not only. It's a signal. It's you telling your own brain to grow."

Deb stopped stretching. She was listening now, both feet flat.

"Say that again," she said quietly.

Maya said it again. "You've been growing new brain your whole life. Every morning. Nobody grew it for you. You did it. With your own two legs."

Deb didn't say anything for a moment. Then she sat down on the bench like her knees had decided for her.

"The doctor said it help," she said. "He never said it grew anything. He never said I was building."

"There's more," Soren said, and Maya could tell he was chasing something now, past politeness, the way she usually did. "It's not just running. Learning does it. New turns. New routes. And, Deb, you always run with someone. You said you can't stand running alone."

"Can't," Deb agreed. "Never could."

"That does it too. Being with people. Three things. Moving, learning, company." He looked at his notebook, then at Maya. "And I read what shuts it down. Being scared all the time. Long, grinding, no-way-out kind of scared. That's the one thing that stops the seahorse building."

Maya sat down next to Deb. "After your husband," she said. "You could have stopped. Sat inside. Been scared."

"I wanted to," Deb said. "Some mornings I really wanted to."

"But you ran instead," Maya said. "So the exact thing that would have stopped you building, you ran away from. Literally."

Deb laughed, but it came out shaky, and she pressed her hand over her mouth.

Maya turned to Soren. Neither of them said it out loud, but the same thought was sitting between them, enormous. Every question they had ever asked, every strange route their heads had ever taken, every hour spent wondering instead of quitting, had been the seahorse building. All of it. Right now. This conversation was making more of the thing having the conversation.

"We're doing it right now," Maya whispered. "Just by figuring it out. We're growing it."

"Sitting still and thinking hard," Soren said. "That counts too."

Deb stood up. She wiped her eyes with the back of her wrist and retied her ponytail.

"One more loop," she said. "You coming?"

Maya was already tightening her laces.