It is a spectacular collision of real and virtual worlds and the consequences are potentially earth shattering.

On the one side, there is South Korea - the most wired place on earth, with an internet that sizzles into 90 per cent of all homes and a national obsession with internet games.

On the other, there is North Korea - one of the most paranoid and dangerously unpredictable places on earth, with a million-strong army and, as this film reveals, a super-secret team of state-authorised hackers looking to bring chaos to its neighbour and beyond.

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In South Korea, millions are addicted to the action unfolding on their screens - games bristling with powerful weaponry, requiring lightning-fast trigger skills to survive and played out on virtual battle grounds.

Internet gaming is a massive phenomenon in a country with super-fast internet, with its own superstars, big bucks and even its own top-rating television shows.

But it also has its downsides.

The number of Koreans addicted to gaming is estimated to be in the millions. So-called PC Bangs in places like the capital, Seoul, are filled with gamers who do not know what time of the day or night it is - and who play for days on end.

A number of murders and deaths have been linked to the gaming obsession, while special psychiatric units have been established to deal with the problem.

But as a generation binges on internet games, a very real enemy is watching and looking for vulnerabilities in the national grid.

Reporter Mark Willacy has tracked down key defectors with first-hand knowledge of North Korea's clandestine cyber operations. They have provided intimate details of a crack team of tech whizzes training their sights on South Korea's computer grid, planting viruses and dislocating and disabling important parts of the system - the financial sector, transport, internet service providers and portals.

So, is it Game On?

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