NESSA O’MAHONY is primarily a poet, the author of three well received collections, and a verse novel. Much of her previous writing has interrogated the subjects of family and history, often dealing in quite innovative ways with how the two intersect.

In her 2014 poetry collection, Her Father’s Daughter, she published a parallel sequence of poems – one relating to her relationship with her own father, whose decline and passing she charted with sometimes aching candour, the second exploring the life of her grandfather, whose story emerges through her mother’s memories and O’Mahony’s own research.

Her latest work, The Branchman, published by Arlen House, is O’Mahony’s first foray into the historic crime thriller genre. Her above mentioned real life grandfather, Michael McCann, returns in fictional form as Michael Mackey, detective officer in the Garda Special Branch which has just been invented by the first Garda Commissioner, and future Adolf Hitler fanboy, General Eoin O’Duffy, and my own near namesake, Minister for Justice, Kevin O’Higgins.

The year is 1925 and O’Mahony’s protagonist is sent to the Garda barracks at Ballinasloe, his main task being “to root out subversion”, of which there was plenty in the aftermath of the Civil War. In this context the word “subversion” was most often a word used by the winners – Cumann na nGaedheal and their allies – to describe those they had recently defeated – the anti-Treatyites – but failed to actually kill or drive out of the country. The novel begins with a quite horrible murder, the investigation of which is first item on the agenda for Mackey upon his arrival in Ballinasloe.

One of the best things about this novel is O’Mahony’s masterful bringing back to life of places like Ballinasloe in the middle bit of the 20th century. An early part of Mackey’s settling into everyday life there is his struggle to find a place to have a quiet drink; no easy task for a Special Branch man, then or now. His superintendant recommends a suitable establishment, though warns that there must be “no shop talk” while imbibing: “The barman knew how to pull a pint, thank god. And the whiskey was Gold Label, even better. One-horse towns had their compensations.”

O’Mahony makes real the settling political sands of the time. Mackey’s own personal history illustrates this well. In 1915 he enlisted in the Royal Munster Fusiliers to fight for Britain in the World War I. In 1917, after the last of the executions of the leaders of the 1916 Rising, he joined the Volunteers (soon to become the IRA ) and was sent to Stockon-On-Tees where his task was to engage in “Arson and arms raids, mostly. The job was to distract rather than defeat…”

Come the Civil War, Mackey took the Pro-Treaty side and was stationed at Castlebar under the colourful, some would say notorious, General Sean McKeown whose job was to “pacify” the west of Ireland for the new Irish Free State. When he meets his ex almost girlfriend Annie on his arrival in Ballinasloe she quips, as is her way, “Detective…They let anyone into the Guards these days. As long as you were on the winning side, or at least claimed to be.” This is a big story expertly told.