Fifty thousand people stood up in order, section by section. There was no warlord, no banner, and I heard no drums of war. Yet, they moved. I saw it coming from across the field. A ripple of bodies. Arms up, then down. Moving toward us like weather. “What is that?” I asked the boy next to me. “The wave. Stand up when it gets here.” “Who started it?” “Nobody knows, man. Somebody.” Somebody. In my land, to move fifty thousand men you need a warlord, a banner, three years of campaigning, and excellent drums. Here, one bored stranger in section 134 raises his arms, and an army obeys. I watched it approach. Section by section. Strangers who will never meet, rising for each other. The man with nachos rose, holding the nachos. The nachos rose too. Nothing was spilled. I do not know how. It reached us. I rose. My arms went up before my honor could discuss it. I made a sound I have not made since childhood. I will not describe the sound. Then it passed, and we sat, and it was someone else’s duty now. “Will it come back?” I asked the boy. “If it’s a good one.” It came back. Three times. Each lap weaker, like an old soldier, until somewhere in the outfield it died, and the whole stadium sighed together — fifty thousand people mourning a wave they had built themselves. No one commands it. No one owns it. It asks, and you answer, and for six seconds you matter to a stranger in section 134. A wave does not recruit. It arrives, and you were always a member. I am told this also happens at football games. I will be attending.