I'm off to Dublin to spend a day fighting viruses, a job which involves exposing myself to bots and worms, Trojans and parasites. They may only be computer viruses, but still I'm worried I haven't had the right injections.
The Irish sky looks grey from the cab window, but one thing is clear: the guys at Symantec take security very seriously - it's impossible to find their HQ. The taxi driver makes several embarrassed circuits of the industrial estate before we arrive.
I meet operations manager Patrick Fitzgerald, who takes me through the massive aircraft hangar of an office and into the sealed-off quarantine area. He tells me that the PCs here are kept separate from the rest of the network, because they deliberately infect them and can't afford to let the viruses spread. I feel like Mother Teresa entering a leper colony.
Here engineers work on virus research, analysis and protection. It's a 24/7 gig, covered in eight-hour shifts by the Dublin team and their oppos in Tokyo and LA. Patrick talks me through the various methods they employ: from the honey-pot - leaving machines exposed to see what happens to them - to lurking around in dodgy internet forums and monitoring private communications to see what the bad guys are up to.
So it's basically just keeping tabs on a few spotty kids messing with the Pentagon's security teams? Not quite. Malware is big business and the stakes are increasingly high. Or, as Patrick puts it: 'It's nuts.'
'This is a new era,' he says. 'It's like Die Hard 4.' I never made it that far through the franchise, but I get the gist: cunning gravel-voiced intellectuals holding nations to ransom by hacking into the unseen computer networks upon which everyday life depends.
I'm not far off. This year's biggest virus threat, called Stuxnet, targets systems running the environmental controls in industrial set-ups - like the pressure in pipelines or the temperature in power plants. It can report back to the hacker on what it's found, gain access to plants and start its virtual meddling.
And it gets even more Hollywood: Stuxnet was started by someone deliberately leaving an infected USB stick in a car park. And 60% of attacks have been on Iranian infrastructure. 'We have only circumstantial evidence, but a nation state is clearly behind it - there's significant cash and technique here.' I'm half-expecting Patrick to strip down to his vest and start crawling through the air-con ducts.
But the Bruce Willis role wouldn't quite fit here. Patrick waxes lyrical about the thrill of the job, but, looking around, it still feels more like a college IT department, populated by a selection of geeks with bad postures, demonstrating various brands of ill-fitting T-shirt.
At lunch I join in the banter with some of the all-male team. The joke is that it's the virus hunters themselves who write the viruses - a kind of viral job creation scheme. 'We don't need to,' says the chap next to me. 'That's like accusing firemen of being arsonists.'
I ask if any of them have ever used their expertise for less benevolent ends. 'He's your man,' says one, deadpan, pointing to a mate. His target looks up at the ceiling and whistles innocently. He's joking of course: poachers turned gamekeepers are not unknown in the industry, but Symantec has a policy of not hiring anyone known to have been a hacker.
The afternoon involves plenty of demos, but the nature of the beast remains elusive. That is, until Patrick's pony-tailed pal shows me a malware toolkit, the kind anyone can get just by looking around on Google. He shows me how to control another machine, how to operate someone's webcam, and how easy it is for hackers to log your keystrokes - very handy for stealing passwords. Intercepting and rerouting bank transfers is only marginally more difficult. Crikey.
Even for the good guys, the temptation to cross over to the dark side must be strong. Do some people in the employ of anti-virus companies work for the other side too? 'I wouldn't be surprised,' he says. 'You get crooked cops, don't you?'
I thought that was only in Hollywood.
But a perfectly aligned spine isn't everything, and it's soon clear that in most other respects I fall well short of the minimum acceptable standard for a professional virus hunter. The problem is that, despite numerous impressive explanations, I just don't get it. There's nothing concrete, just code.