Even on holiday, film-maker Felix Chong does not stop being productive.
Speaking in Mandarin over the telephone from Hong Kong, he tells Life! about the inspiration for his latest work.
"Be it in Taiwan, China, Australia, Thailand, Malaysia, the cab driver's grouse in every place was the same - property prices are too high," he says. "I always thought it was a problem specific to Hong Kong, where we have this saying cun tu cun jin (an inch of land equals an inch of gold)."
This led to the property-themed surveillance thriller Overheard 3, which is currently showing in cinemas. The film details a complex web of interests and relationships in Hong Kong's New Territories and stars Louis Koo, Sean Lau Ching Wan and Daniel Wu.
Elaborating on the phenomenon of rocketing prices, Chong says: "It seems that everyone has given up many of their ideals in the pursuit of property. I hope that this movie can make people ask why their hard work is not even worth a pile of bricks."
The Overheard series may be cloaked in the genre of crime thriller but it also has something to say about hot-button topics from the manipulation of the stock market in Overheard (2009) and Overheard 2 (2011) to Overheard 3's profiteering property tycoons.
Writer-directors Chong, 46, and Alan Mak, 46, have helmed all three films together.
And it turns out that being inside a vehicle is productive for them as a pair as well.
The two have their own production outfit, Pop Movies, and they would travel in the same car to get to the film set. Chong says: "After discussing the work for the day, we would soon find out who is more inspired that day and he would take the lead. The other one might not even say a word the entire day."
They have certainly figured out what works for them, but that does not make it any easier to come up with a new instalment for a series.
As Chong puts it: "As we go along, it gets harder. We hope that the style and storytelling method of the three films are different."
This makes it more challenging for the film-makers but he sees it as being fair to the audience. "If every film is roughly the same, then it's like watching the same film for them," he says.
They are also fair to the three leads as the focus has shifted from Lau in Overheard to Wu in Overheard 2 to Koo in Overheard 3. Chong says with a laugh: "Each of our films is about fairness and justice, so do you think we are being fair by doing this?"
Beyond the three leads, Overheard 3 has a sprawling cast. Chong counts 21 characters in all, and 14 of them are fully fleshed-out with background stories. Juggling that and the multiple threads of the storyline must have been tricky.
He quips: "After writing the script, it doesn't seem so complicated.
"But at every juncture, we have to ask ourselves: Is our story simple enough to follow? Is it clear? So we have to be very sure of what we want before we film each scene."
He has worked with Mak since 2001's dramedy Final Romance and, over the years, they have often proved that two heads are better than one. Their best- known work is the commercial and critical hit that is the crime thriller trilogy Infernal Affairs (2002-2003). Chong co-wrote the scripts with Mak but did not co-direct the films with him.
And the one thing that Chong has learnt from his years of movie-making is this: "When I make a film, the most important thing is that I have to feel that it's fun. Only then will the audience find it fun as well."
Trying to tailor a film to appeal to the tastes of audiences is an exercise in futility. When Infernal Affairs first came out, opinion was fiercely divided.
He recalls: "After the film's premiere, I was walking along the cinema's aisle and many people were saying that it was terrible. I have no idea how it suddenly turned into a classic. It's very hard to tell what audiences want."
Chong is married with a 12-year-old daughter, who watched the film at the age of nine or 10. She found the crime thriller "hilarious".
He explains: "She's good friends with Chapman To and she found his death very sudden and wondered: 'Is it so easy for someone to just die?'"
Personal connections aside, Chong has a message for those who watch his films: "On the outside, the films might look like crime thrillers, so audiences approach it with certain expectations. But just relax and follow our film's story. What's fun about movies is that they take you into an unknown world."
Overheard 3 is showing in cinemas.