The film is a breath of fresh air from the typical HK "crime drama" genre otherwise encumbered by formulaic plots, predictable character persona, and inane moral proselytizing. Sadly, it fails to live up to it's own aspirations and ends up defaulting on precisely what it needs to distance itself from.
The story revolves around three members of a police surveillance squad conducting an investigation into a financial investment group involved in criminal fraud. The focus of the plot, however, is actually on the three officers themselves who stumble upon an opportunity to capitalize on the information they gathered during their surveillance. The audience is given insights into the personal issues they are grappling with, the relationship between them, and why the temptation to breach their moral duty and professional obligations is so powerful. The temptation they confront and the attendant reasons that compel them to succumb to it become the very device that turns them into the film's antagonists.
Sadly, the script then makes a wrong turn. Instead of allowing this plot to unfold, it is shelved half-way through the film and becomes a side-plot to a criminal conspiracy involving murder, kidnapping, and revenge, rendering the film from an interesting exploration into a run-of-the-mill crime-drama action flick. None of the actors seemed particularly interested in their roles after that, with perhaps the exception of Michael Wong, who plays the head of the investment group with his usual steel-cold glare and villainous flair. He actually makes an entertaining performance in the latter half of the film when he receives more screen time because no one else seemed nearly as excited to be involved in this project anymore.
I don't know why the film's name was translated to English as "Overheard" since the electronic surveillance devices they used were also visual and not just audio. Perhaps something got "lost in translation", like the intention to produce a complex and interesting film.
