“Ecotone. It means an in-between spot. Eco, like ecosystem. And tone, from tonos. That’s Greek. It means ‘tension.’ So it’s like the tension between ecosystems, you understand? The overlap between two worlds. Two worlds in conflict with each other. You see all that land behind us?” He pointed a thumb back at the soft rolling grassy hills. “That land wants to be prairie. But this here land in front of us, it wants to be forest. And this spot, this is where the prairie and the forest are fighting. And this little guy”—he brushed the baby elm gently with a finger—“he’s the advance guard. There’s a slow-motion war happening right here, Jack, beneath our feet, on a scale we can’t even imagine.”