Cyclist impresses, wins medals and events only to be found out as a drugs cheat. The truth will come out at some point—as Lance Armstrong found out, to his detriment.
These things never go away. If a cheat beats the testers one year, there's new evidence and testimony that eventually creeps up and bites them. It lurks around the corner, at the bottom of every test tube or on the tip of the tongue of an aggrieved foe.
Call it science or just plain karma, few cheats can dodge their fate forever.
On the eve of the 2016 Rio Olympic Games, Team GB's Lizzie Armitstead has found herself under the same sort of scrutiny as Armstrong.