THOSE WE LEFT BEHIND by STUART NEVILLE (2015, Vintage, 362pp) ∗∗∗½ Blurb: When 12-year-old Ciaran Devine confessed to murdering his foster father it sent shock waves through the nation. DCI Serena Flanagan, then an ambitious Detective Sergeant, took Ciaran’s confession after days spent earning his trust. He hasn’t forgotten the kindness she showed him – in fact,…