Jared Savage, one of our finest investigative journalists, gets a wider canvas with Gangland and produces a fascinating true-crime page-turner which looks at the changing face of organised crime in Aotearoa New Zealand.

He starts with a man he describes as New Zealand’s answer to Breaking Bad’s Walter White. Classic car enthusiast William Wallace was in his mid-50s when he was made redundant by Air New Zealand where he had worked as an industrial chemist. Wallace, armed with a copy of Secrets of Methamphetamine Manufacture, upskilled and started a very profitable new business. Gangs saw the opportunity too – suddenly co-operation, not conflict was the new normal – so manufacturing meth, at least in the late 1990s before the drug was reclassified, was seen as a low-risk crime with massive rewards.

But the Wallace case seems almost quaint compared with what follows as Savage takes us to the present day via 11 other police drug operations, some of which he covered as an award-winning crime reporter for the New Zealand Herald. We follow both the growing sophistication of gangs and their international partners to get drugs into the country and the cop’s attempts to stop them.

Savage lets the stories speak for themselves – and what stories they are. Many are disturbing – executions, beatings, blackmail – but there’s comedy and ineptitude too.

One on-the-run Ferrari-driving meth cook, was only apprehended when he stole a $2.80 item from a PAK’n’SAVE while the chapter Comedy at Sea, which looks at how a Northland policeman stumbled on 501kgs of meth in a campervan, has to be read to be believed.

In another operation, police gained valuable intel when a meth-dealer failed to hang up his phone. The ensuing dinner conversation was recorded to another's voicemail which the cops were listening into.

That soon led to an unusual raid on a remote farmhouse where the Armed Offenders Squad hid in the back of a horse float to camouflage their approach, jumping out at the last opportunity.

Savage is adept at moving through often complex cases quickly, without sacrificing accuracy. Many read like mini thrillers. In each, he focuses on a few key characters: the garrulous Felix Lim who unwittingly introduced an undercover officer to some high end targets or the fearsome dairy farmer Max Beckham who turned to using and dealing meth after the accidental death of his two-year-old son. It's a deft way of keeping the narrative moving.

There are some familiar names here too: “jail house lawyer” Arthur William Taylor who escaped for a time from Auckland Prison at Paremoremo and went on to run an international drug operation from his prison cell; Head Hunter’s president Wayne Doyle and legendary Auckland crim Waha Saifiti among them.

Of course, once the money's made it has to be washed so Savage follows the money. A yum cha restaurant here, a dodgy finance firm or, in one case, an elderly Vietnamese woman who would fly into Auckland from Sydney to collect bags of cash which were handed over in broad daylight in some of Auckland's busiest streets. Then there's that old standby, gambling. Savage notes that one woman, Yixin Gan, put $1 million across Auckland’s SkyCity tables; she is now serving a 14 year prison sentence.

In the chapter focused on Killer Beez president Josh Masters, Savage keeps out of the way and lets the prosecutions' summary of facts tell the sad story as Masters ended up a paraplegic shot by his best friend turned gang rival in an Auckland Harley Davidson dealership.

Occasionally Savage hears directly from a key participant. As luck would have it, the aforementioned Felix Lim was on his first overseas holiday in 20 years when the police moved in, dodging a hefty prison sentence. He called Savage from Malaysia vowing (wisely) never to return to New Zealand.

While Gangland focuses on the dealers and money men, Savage’s epilogue suggests that no matter how efficient our police force, the meth problem can only begin to be solved through a health-based approach focused as much on demand as supply. Despite the success of the operations, he points out that meth is today easier and cheaper to get than ever before in Aotearoa New Zealand.

From the halycon days of 1990s clan labs to today's Aussie import “Nike bikies” with their Rolex watches, model girlfriends, gym routines and international backers, Savage's account is a compelling glimpse into a world, “where millions of dollars are made, life is cheap, and allegiances change like the flick of a switch”. A must-have for true-crime fans this Christmas.

Reviewed by Greg Fleming