Having worked as a hack for almost 20 years, I am used to seeing former colleagues going over to the Dark Side. Whether it's to public relations or the bureaucracy, most of us eventually can't resist the higher pay and more stable hours. I pride myself on having the purity of Luke Skywalker, mainly because I couldn't write a sentence or open my mouth without upsetting some person or organisation, a personal defect highly unvalued in the PR industry. So I am glad one of us has gone in the opposite direction and taken his calling to a higher level - the world of private investigation. One Investigation, newly set up reportedly by a former chief of a leading newspaper's paparazzi team, has launched a high-profile publicity campaign, but it would not confirm the identity of the boss, saying it would compromise the nature of its work. The seven-strong investigator team specialises in tracking unfaithful lovers and spouses, naughty domestic helpers and drug-taking children as well as commercial crimes. They don't come cheap. It is not among the most expensive private eye firms, which can charge upwards of HK$15,000 a day. Still, you are paying good money to find secrets that might break your heart.