The Breathing Forest

The cathedral inside you has weather — and here is where it lives. Spread both your arms as wide as they will go. That wingspan, tip to fingertip, is the total surface area folded inside your chest. Not the size of your lungs from outside, which fit in two cupped hands. The size of what is hidden inside them: a branching tree of tubes that splits, and splits again, and keeps splitting for twenty-three generations until it ends in three hundred million tiny rooms, each one thinner-walled than a soap bubble, each one pressing against a blood vessel so fine a single red cell must turn sideways to squeeze through. Air on one side. Blood on the other. A wall one cell thick between you and suffocation. This is not a passive organ waiting to be used. Right now, without any instruction from you, it is making decisions. The small tubes are tightening or loosening. Blood is being redirected toward the parts currently receiving air, away from the parts that are not. The lung is routing itself, the way a city reroutes traffic after an accident, except it does this ten thousand times a minute and has done it every minute since before you were born. You have never once told it to. And here is what nobody tells you: the last breath you will ever take has already been decided by a cluster of neurons the size of a grape, sitting at the base of your skull, that you will never feel and never find.