The Irish writer Paul Lynch’s Booker-longlisted fifth novel, Prophet Song, is a book of encroaching terror, an atmosphere of foreboding seeded from its opening lines where “the dark gathers without sound the cherry trees. It gathers the last of the leaves and the leaves do not resist the dark.”  Larry, a trade unionist, comes to the attention of the sinister-seeming new GNSB branch of an alternative Ireland’s gardaí and, after going on a march with fellow teachers, doesn’t return home. This is the first of several escalating disasters which befall his wife Eilish, a molecular biologist by training, and her family. It’s through their increasingly tortuous experience that we feel the creep from veiled authoritarianism to total outrage. From the beginning, there is a proliferation of questions, as Eilish and her baffled children try to find out Larry’s whereabouts, but also how far this new government is willing to go in its attempts to control the nation.…