Film emerges from Dhaka, Bangladesh, where the roads are awash with a river of blood. Witness Amir Hussain fears it is a warning from god. It is reminiscent of the blood rains that have fallen around the world. Chemist Kishore Hari analyzes the footage and suspects another cause: a horrific industrial accident. If he's right, and this has come from the city's tanning industry, then it could be contaminated with deadly arsenic.