It’s write-your-own-joke time. Submit them in the usual manner (Twitter, Facebook, or via Comments.)
The raw materials: A pile of white powder is discovered first thing one morning by a forest ranger by the side of a tree on Wanstead Flats. Once alerted, the authorities take it seriously. Three nearby roads are closed. The experts come in. Warnings of a chemical spill spread. Friday morning traffic is badly disrupted. Two hours later, the chemical tests show the substance was sugar.