In Glasgow, the mob is one. The Family, a collective of twelve heavy crime families, has formed to fight the influx of migrant gangs. Glasgow has a new menace, however, with the arrival of an ISIS cell which kidnaps a police officer. The Family has eyes and ears on the streets, and Police Scotland need it to find the cell and save the police officer. Sean Rooney, erstwhile forensic profiler and psychosleuth, now Father of the Family is pivotal to this. Suffering mental illness with godly delusions, can he employ his `twelve disciples' and save the police officer and the city against ISIS, now increasing in strength with an influx of soldiers arriving with migrant gangs and asylum seekers into the city? Killers, gangs, terrorists generally have a reason for murder, e.g. love, sex, money, power, honour, religion, revenge! But Sean Rooney, a good man, what is his reason?