For a man who once made it to Time magazine’s list of the 100 most influential people in the world, John Green is almost absurdly understated. Everything about him seems an exercise in drawing the least possible attention to himself. Which is why I find myself in a remote suburb of Indianapolis searching for an unmarked office in an unmarked alleyway between a cafe and an ice-cream parlour.

There is only one possible door in the narrow alleyway. It opens with a push (no intercom, no security) and I take the lift to the top floor, as instructed. The first person I see as the door slides back is Green himself, grappling with a coffee machine that is refusing to dispense coffee. “Oh hey, you