Like his stunning “The North Water,” Ian McGuire’s “The Abstainer” pits good against evil, but this time the devil, ex-Civil-War hard man, Stephen Doyle, come to nineteenth-century England to wreak death on behalf of Irish terrorists, rides in nuanced with war’s burdens. And this time the steady hero, policeman James O’Connor, sags under the burden of family loss and alcoholism. When O’Connor’s valiant tracking efforts are subverted, his world unravels. The author writes dense, propulsive prose that evokes the dark, dank times and captures the intrinsic savagery of the battle between the Irish and the English. As in “The North Shore,” the result is a tale of unfettered brutality and inexorable tragedy. However, “The Abstainer” lurches rather than glides through the story, and the duel between troubled cop and troubled killer somehow fails to achieve gravity. Even the Cormac-McCarthy-homage of a finale, impressive as it is, cannot lift this dark tale above the tale itself. A fine read but not a patch on its predecessor.