THE world's best athletes will power their way through the smog of Beijing this morning as the first events of the Olympic Games begin.
It is the once-every-four-years sporting extravaganza the world waits for and seemingly can't get enough of for the two weeks of competition.
And for sports fans it is the chance to marvel at the skills of supreme sporting performers.
But how much of what we see will be the genuine result of talent and hard work, and how much will be helped by medical science.
Drug cheats are given plenty of warnings but many remain prepared to run the risk of detection as they pursue the lure of Olympic gold.
Some will stop at nothing - including risking their health - to get the edge over their rivals.
It becomes depressing to watch stunning athletic feats and then later learn the performer had an unfair advantage.
The pursuit of drug cheats is a thankless task as those policing the rules can't help but be one step behind the latest dark developments by the chemists.
But it is a task that must continue, for attempts to stop the cheats are the only things that prevent great occasions like the Olympics from descending into farce.