Two days later, a box marked arrived at his door.

Golden Mystery Snails that looked like polished river stones.

Leo opened it with surgical precision. Inside, nestled in thick layers of insulated foam, was a sturdy, double-bagged pouch of water. The fish was there—moving slowly but alert, its colors slightly dimmed from the darkness. The Acclimation Leo followed the instructions perfectly: for 20 minutes to match temperatures.

—never pour the shipping water into the tank.