The fifth (and I'm assuming final) entry in David Lam's Storm series. Apparently, I missed the third and fourth films, it might just be that I messed up because of the somewhat confusing naming scheme of the series. Not to worry though, these films work well enough as stand-alone entries, I'll catch up with them afterwards.
The ICAC get involved with a human trafficking case. When they want to apprehend the criminals, they turn out a lot more violent than expected and get away, while killing some cops and immigrants in the process. The case gets even more complicated when the brother of one of the ICAC cops turns out to be part of the gang.
A pretty typical Hong Kong police procedural, but it's clear the money simply isn't there anymore. There are some decent action scenes and Koo is perfect for the part, but the film itself looks a bit plain and the story is pretty rushed. It's fun enough filler, with some stand-out action, but nothing more.