Up past Bride's Pool and into the scenic highlands of the Pat Sin Leng country trail, a young couple stride. Even in this chilly weather, they enjoy the sweeping views of Mirs Bay, stark peaks and lush ravines. They carry all the normal paraphernalia of the Hong Kong hill walker; plastic water bottles, ski poles and mobile phones.
But this attractive young couple have extra baggage. Inside their colourful windbreakers are packed police special revolvers.
No ordinary hikers, this pair, but undercover trekkers of the Picnic Patrol. If gangs of illegal immigrants hiding in the hills confront this young man and woman, they are in for an unpleasant surprise. Instead of netting wallets, watches and mobile phones, the would-be robbers are likely to spend several years in jail before being deported.
In an imaginative move to aggressively take law enforcement to where it is most needed, commanders of New Territories North region have sent their teams into the high country.
It's a move aimed to prevent crime and protect people before they become victims. All this year, illegal immigrants have been coming over the border.
There were 1,211 caught in January, the highest monthly total, and 705 in June, the lowest. In October, there were 989 arrests, with 810 in November.
Experience and statistics show that Cantonese illegal immigrants are here for work. They want jobs, which unscrupulous building site foremen and others foolishly give them.
But about half the illegal arrivals these days are from further into the interior. Many of these are attracted by the chances of a get-rich-quick hit. They come to rob.
The easiest targets for robbers who have managed to evade arrest coming over the border are hikers. Senior Superintendent Michael Yip Suen, Operations Commander of New Territories North Region, and Superintendent Danny Lawley, his deputy, came up with a strategy aimed at warning hikers of the danger and snaring robbers.
The Pat Sing Country Park covers almost 70 square kilometres, most of it hilly, with five major tracks. Every Sunday and public holiday, crowds flock there; last year, about 1.8 million people went walking over Pat Sing Leng, Plover Cove and Taipo Kau trails.
When the hiking season started in October, police were ready. A platoon from the Quick Response Team was posted around the parks.
At the start of tracks, uniformed policemen with command vehicles are obvious. Along the trails, groups of uniformed police are on patrol. Mingling with the hikers, are undercover teams.
The effects of this strategy are obvious. Hikers see police as they start their healthy walks; they are reassured.
In the hills, both walkers and potential criminals can spot the uniformed patrols. That puts a spring in the step of the weekend walkers and makes criminals think twice.
Then along come a boy and girl. If robbers pounce, they are likely to find themselves handcuffed and arrested.
Part of the Picnic Patrol tactics are also to have two-man units studded on the hilltops, keeping a lookout through binoculars to spot potential trouble-makers.
Our country parks are one of the greatest of community assets. They are the people's playgrounds. They give every family in Hong Kong a vast backyard in which to enjoy the open air.
So the discrete but effective methods adopted to keep people safe while issuing a stark warning to potential wrong-doers are welcome.
Kevin Sinclair is a Hong Kong journalist