DID you hear the one about The Prodigy, The Missile and The Professor? Well they're about to walk into a pool in Adelaide and lock horns in an old-fashioned 100m freestyle shootout, and who wins is anyone's guess.
There's Kyle Chalmers, who at 17 could be anything, James Magnussen who is reloaded and gunning for Olympic redemption, and Cameron McEvoy whose intellect has earned him a nickname fitting his other goal in life - to become an astronaut. 
But all three of Australian swimming's hungry young stars won't fit into two individual spots in the 100m for the Rio Olympics, which will be decided in Adelaide from today.
Heats and semi-finals in swimming's blue riband event start this morning and the top eight will make it to the final tomorrow night that will also determine the team for the 4x100m freestyle relay for Rio in   August.
It was in this very pool at the SA Aquatic and Leisure Centre four years ago that Magnussen went 47.10 seconds - and he hasn't been that fast since.
After finishing second in London, then rebounding to win the world title 12 months later, Magnussen says he has unfinished business to take care of in Rio.
On the comeback trail from shoulder surgery last year, Magnussen's coach Mitch Falvey says the 24-year-old is primed.
"His prep has been fantastic and his rehabilitation has been incredible," Falvey said.
Falvey said having a 17- and 21-year-old snapping at his heels had spurred The Missile on but his motivation came from within - particularly a desire to better the silver medal he won in London in 2012.
McEvoy is the only one of the three also racing the 200m at this week's trials where he made last night's final.
His coach Richard Scarce said McEvoy's training had been tailored to prepare him to back up with as little recovery time as possible. So is Chalmers a serious threat?
"He's a real threat, absolutely," Scarce said. "He's improving all the time ... he's got a great attitude.
"But still there's a lot to the race, Maggy will be determined to get to the Olympics, he's been there before and has the fastest time we've seen in a long time four years ago. You can't discount any of them."
JAMES MAGNUSSEN 'The Missile'
Age: 24 Lives: Sydney Height: 195cm Weight: 94kg Coach: Mitch Falvey Honours: 100m world champion (2011, 2013); 100m Olympic silver (2012). 100m PB: 47.10 50m PB: 21.52
CAMERON McEVOY 'The Professor'
Age: 21 Lives: Gold Coast Height: 183cm Weight: 73kg Coach: Richard Scarce Honours: 100m silver medal world championships (2015).
100m PB: 47.56 50m PB: 21.73
KYLE CHALMERS 'The Prodigy'
Age: 17 Lives: Adelaide Height: 194cm Weight: 94kg Coach: Peter Bishop Honours: 50m, 100m junior world champion (2015), 4x100m medley relay silver medal world championships (2015).
100m PB: 48.4250m PB: 22.15