Northern Mexico’s indigenous, rural Tarahumara are some of the world’s best endurance runners. Facing drought and famine, some members of this reclusive tribe have been lured into carrying drugs into the US for Mexican cartels ─ literal drug runners. As cartel violence worsens and groups take over the tribes’ lands to grow marijuana and opium poppies for the drug-hungry West, the Tarahumara’s fate is uncertain, but it doesn’t look good.