On 18 October 2019 a group of Chilean school pupils began a campaign of fare dodging on the metro in Santiago. In stations across the centre of the capital exuberant teenagers leaped over turnstiles while chanting: “Evadir, no pagar, otra forma de luchar” (“Evade, don’t pay, a different way to fight!”). Their grievance was a small one, a 30 peso (about $0.04) hike in ticket prices. But it proved the spark. And Chile, long held up as a beacon of prosperity and stability in Latin America, turned out to be the tinderbox.