India, Aug. 31 -- Dear Reader,

I am walking down the hillside to buy bread when I hear a roar.

It is the Manalsu river, named after the ancient sage Manu, the same sage Manali is named after. But today the river is different to anything I've ever seen before - gone are its icy green glacial waters. Instead it's a roiling, broiling, seething sea of mud straining against its bank, rumbling with uneasy undertones.

"The river is angry", says the man at the bakery. "The Manalsu doesn't get angry, but this time things have gone too far."

On my return home as I cross the bridge over the Manalsu, I look down again at the river and feel fear. I think back to a book about rivers that has been haunting me ever since I read it. The author, the fa...