Hollywood has been good to Dennis Lehane.

The Boston-born author broke through to the big league on the back of Clint Eastwood's Oscar-winning adaptation of Mystic River in 2003, although discerning readers of crime fiction were already aware of his name from his 1990s novels featuring private investigators Patrick Kenzie and Angie Gennaro. The fourth in that series, Gone Baby Gone, hit the screen in 2007, marking the directorial debut of actor Ben Affleck, while Martin Scorsese and Leonardo DiCaprio added their credentials to the psychological thriller Shutter Island in 2010. Last year Lehane wrote the screenplay for crime drama The Drop, which was based on one of his short stories.

A lesser writer might have been dazzled by film industry pay cheques but throughout this period, which also included work on teleplays for The Wire and Boardwalk Empire, Lehane has continued to deliver books that stand head and shoulders above the typical output of the crime genre. Perhaps his novelisation of The Drop can be seen as a cash-in on material that was ready to hand but Moonlight Mile, the sixth Kenzie and Gennaro instalment, added a poignant air of world-weariness to the series.

Best of all, though, was The Given Day, Lehane's masterpiece set in Boston in 1918-19, which packed a lifetime's worth of incident - the end of the First World War, the early civil rights movement, the Spanish flu pandemic, Bolshevik terrorism, Babe Ruth, J Edgar Hoover and the Boston Police Strike - into just over 700 pages. Its ambition stretched far beyond crime genre confines and yet when Lehane wrote a sequel - 2012's Live By Night - he trimmed back the national drama, embraced many of the traits of the 1930s gangster movie and switched his focus to one of The Given Day's minor characters, Joe Coughlin.

Now comes World Gone By, a direct sequel to Live By Night, picking up Coughlin's underworld affairs in Florida and Cuba during the Second World War. The new book shaves away even more of the trilogy's literary expansiveness in order to leave behind a pure, hard example of the gangster genre, its moments of violence gleaming like sun-bleached bone.

Coughlin's discordant sense of honour, as well as his Irish background in an Italian "business" world, sets him apart from his peers. Even if that seems like a bit of a cliché, the acts that stain his soul by the time the book reaches its blood-soaked climax are no less affecting. There's always a deeper level to the loyalty/betrayal moral seesaw in Lehane's books, and here it's embedded in the relationship between Joe and his young son Tomas.

Joe is acutely aware of his own loveless childhood ("You were the child that was supposed to fill the distance between your mother and me" his police chief father told him in Live By Night), and Lehane makes the emotional impact of his story hit harder by juxtaposing key action set-pieces with the innocence of children. The book's final shootout is filtered through Tomas's panic - "Even to his own ears, [Tomas's wailing] sounded alien. It was a cry of such outrage and terror" - and is unusually immediate and utterly devastating.

In terms of plot, World Gone By is driven forward by an against-the-clock mystery: Coughlin, a popular man in his profession because of the money he makes for his associates, is told there is a contract on his head. No one knows who wants him dead, only that the hit will happen a few days hence on Ash Wednesday. It's an effective thriller concept, and Lehane is terrific with his action scenes and colourful with his supporting cast. But it's the moral conflict raging within Coughlin that make this book such a satisfying experience. It's useful, therefore, to have read Live By Night first, not for narrative continuity but for the cumulative weight Lehane brings to the lead character, the very element that makes the reader care.

There's a film adaptation of Live By Night due out next year. Ben Affleck will direct, Leonardo DiCaprio is a producer. Hollywood is still being good to Dennis Lehane; but Lehane isn't short-changing the publishing industry either.