A central figure in the current drama surrounding Essendon and supplements allegedly taken by players during the 2012 season is a man of mystery and intrigue with a rugby league background and past links with Essendon's controversial fitness guru Dean "The Weapon" Robinson.
Stephen Dank left Essendon abruptly towards the end of 2012 amid questions over his conduct, after a bulked-up squad which soared to second early in the season plunged to 11th on the rough end of one of the more catastrophic runs of soft-tissue problems in recent memory.
As the AFL's integrity unit and Australian Sports Anti-Doping Authority probe the nature of supplements given to players during 2012, who knew about them, who ordered players to sign waivers and, if illegal supplements were taken, just how high up the Essendon food chain the knowledge went, Dank and Robinson are likely to be key witnesses.
Robinson had worked at Geelong under Mark Thompson, before heading to the Gold Coast to put muscle on the young Suns.
Thompson played a key role in his move to Essendon. Dank had a history with Robinson dating back before his stint with the Cats.
They worked together as fitness and conditioning experts at Manly in the NRL as far back as 2005 - a time when Dank created his own reputation for being unconventional and somewhat mysterious.
In 2004 he had been hailed as a ground breaker and world sports science leader for his work at the Sea Eagles, researching players' DNA and using it to tailor training programs that would maximise their improvement.
He also was a pioneer in using GPS tracking in training sessions to monitor player loads.
But by 2008 Dank was also affectionately known as something of a mad scientist after the Sea Eagles had flirted with the idea of injecting players with Actovegin, derived from calf blood, which is said to accelerate recovery and muscle repair.
In 2007, Geelong's Max Rooke used the treatment in Germany to help repair a troublesome soft- tissue problem and take his place in Geelong's premiership team.
Eyebrows were raised about Dank in 2008 after the Sea Eagles had completed a 40-0 grand final demolition of Melbourne.
He added to the intrigue by declaring he did not do media interviews while Manly denied that they had injected their players.
He is said to have had a less happy association after shifting to rival club Cronulla where he clashed with the club's doctor.
Actovegin was not illegal or a banned substance. And it is yet to be proved that Essendon players took banned substances in 2012.
But Dank's sudden departure, along with that of football manager Paul Hamilton, the man Dank would have answered to, combined with allegations that players were made to sign waivers, have left plenty of grist for the rumour mill.