Johno applies himself to the baffling business of being a dad with the same determination that he brings to forging a life on the straight and narrow as a bar-owner.
Danny is different. He's a social cripple, acutely sensitive and vulnerable, and a phenomenal artistic talent. He's about as different from Johno as it's possible to be. But Johno assembles a team to nurture him - a lecturer in fine arts who frequents the bar, a matronly neighbour - and Danny befriends a homeless man in the park: vodka-swilling, poetry-spouting Frederick. Frederick is a kind of soulmate, the only person of his acquaintance who understands Danny's artistic vision and temperament.
Meanwhile, McNeil is still doing time, having carried on in crime after Johno cleaned up. He befriends the Italian inmates of the maximum security prison where he's banged up, and they welcome him into their crime "Family".
McNeil is eventually released, and duly takes his place in the Italians' drug empire. When Danny becomes addicted to cocaine after a tragedy, it becomes inevitable that the divergent streams of Johno's past will come together, with perhaps catastrophic consequences.
The first 40-odd pages of Frederick's Coat are pretty desultorily written. But somewhere in the course of the awkward reunion between Johno and Evelyn after he gets out of Long Bay, the narrative comes alive.
Duff has created genuinely interesting characters, and there is plenty of tension: strangely, for all his toughness, Johno is just as vulnerable as his delicate son, and you badly want his heroic efforts to make an honest man of himself to succeed. You fear a relapse, at least as you fear for Danny's safety, a tender, van Gogh-like figure in a very cruel world.
There are plenty of familiar aspects for those who know Duff's work. His recurring preoccupation - that even the worst behaviour in society derives from the perpetrators' misguided attempts to find the love of which they were deprived as children - is here, front and centre.
But whereas Duff has cast about in recent times to get the balance right in his storytelling, he more or less nails it in Frederick's Coat. Violence is an integral part of the tale, but there is a commendable restraint that gives the writing all the more power.
All-in-all, Frederick's Coat is an impressive return to form.