Two images from farmer protest in Madhya Pradesh have stuck with anyone who's seen them, a crowd reciting the Hanuman Chalisa before setting off on a 70-kilometre march, and that same crowd, two days later, walking past broken police barricades with the national flag held high at the front. Both point to a grievance that's been building for weeks over a crop most people outside Madhya Pradesh have barely thought about: moong. Here's what's actually driving thousands of farmers to walk into the state capital.