It's 1969, ten years after Little Gangsters, and Denny and Frankie have graduated from petty crimes to being part of the Di Napoli crime family. By night, they run an illegal gambling club for the mob, kicking the nightly 'taste' up to their crew chief Vic 'the Gentleman' Ciccone,who then passes part of it up the chain to Al 'the Baker' Di Napoli, the family godfather. Denny and Frankie see a good income from the club and it's a good life, but Denny has higher ambitions.

During the day, Denny runs his network of soft drug dealers all over the lower mainland and is one of the main sources of marijuana and hashish for the burgeoning hippie community in Vancouver. People call him 'the Plumber' because he makes his deliveries and collections in an old plumbing van. The trouble with his secondary income is that the Di Napolis frown on drug dealing, leaving that trade to the rival Capello family. But drug sales are making Denny wealthy; he earns more in a day than the average working Joe makes in a month and already owns the Commercial Drive building the gambling club is located in. Even still, Denny wants more.

The mysterious Mister Cho is the '489' or 'Mountain Master' of Vancouver's only Triad, whose main income derives from importing heroin, and Denny wants a piece of it. By adding heroin to his product line, Denny's annual income will rise from six figures to seven. However, Denny doesn't realize that entering into the heroin trade will bring all manner of new troubles to his doorstep. First; he discovers the love of his life, Carrie, is heavily addicted to his new product, and second; a violent rival gang wants what he has. There's also the constant tension of keeping the dangerous Mister Cho and his Triad happy.

Set amidst the free love atmosphere of the late sixties, Denny finds himself walking a tightrope as he tries to help Carrie kick her addiction, fends off a rival gang, and carries out more and more violent tasks assigned to him by Vic. Can Denny maintain it all while keeping the people he loves safe? Or will he crash and burn like so many overreaching gangsters do?