Lena had spent three weekends building her go-kart from old pram wheels and a wooden crate, and it showed. The paint was uneven and one wheel wobbled like a loose tooth. Beside her at the starting line, Marcus polished a kart so shiny it could have been in a shop window.

"Nice, um, crate," Marcus said, smirking.

The flag dropped. Marcus shot ahead at once, but halfway down the hill the course curved sharply past the fig tree. His gleaming kart, built for speed and nothing else, slid wide into the hay bales. Lena's wobbly wheel rattled, gripped, and carried her around the bend. She crossed the line first, laughing so hard she could barely steer.

Afterwards, Marcus wandered over, no longer smirking. "How did you corner like that?" he asked. "Wide wheels at the back," Lena said. "Want to see?" They spent the rest of the afternoon under her crate, talking axles.