Dr Bartone detailed the history of Covid dating from its birth in China last year to the gradual spread around the world .  For months Australia has felt optimistic about containing Covid-19, but a resurgence of the virus in Melbourne has put those efforts at a critical stage.
About 300,000 people were ordered back into lockdown this week amid a military-assisted operation to "ring fence" 10 postcodes at the centre of the outbreak.
The problem has escalated in the past fortnight - there were  482 active cases in the state of Victoria.
The numbers remain below Australia's March peak, but what's concerning to authorities is that local transmission which is now the key source of infections.
Previously, most cases were coming from travellers returning from overseas. Australia's curve flattened rapidly three months ago with the enforcement of lockdowns and mandatory hotel quarantines for people
entering the country. It has had about 8,000 cases in total and 104 deaths.
In every other state, the virus has been dramatically slowed or eradicated. So what's gone wrong in Victoria?
There has been failures in hotel quarantine
Premier Daniel Andrews has pinpointed the origin of many infections to workers who were overseeing hotel quarantines breaking the rules. More than 20,000 travellers have gone through 14-day quarantine in the state.
A report which traced Covid-19's mutation in Victoria found that hotel staff cases were the "ancestors" of ones found later in suburban homes.
So how did the virus spread? Allegations of blame have been levelled at private security firms contracted to operate the state's quarantine. Neighbouring New South Wales took a different approach - using the police force.
Below it the graph of cases this year
Victoria has faced accusations of systemic failures such as guards being improperly trained or not given enough PPE.
Mr Andrews has also described cases of illegal socialising between staff, listing examples of workers sharing a cigarette lighter or car-pooling. Local media also reported claims of sex between guards and quarantined travellers.
The government has ordered a judicial inquiry into their quarantine operation and fired the contractors.
Unlike in many states, the virus had been 'seeded'
In early May - during Australia's lockdown - authorities expressed concern about a virus cluster among workers at an abattoir in Melbourne's west.                                               About 111 cases were eventually linked to the site, which had been the subject of a rapid trace-and-track response from authorities. Lockdown restrictions eased a month later, allowing people to again visit friends and family, and enjoy other freedoms such as eating out at restaurants.
But experts believe that secondary cases from that cluster - and possibly others - were still festering undetected in the community.
At the end of his speech, Dr Tony was flooded with questions
It was a stimulating Rotary meeting