Between 2016 and his retirement in 2022, Assistant Garda Commissioner John O'Driscoll was the public face of garda operations targeting organised crime. This put him at the centre of a long-running quest to bring about the demise of the Kinahan drug cartel, culminating in US sanctions being imposed – an unprecedented development, spearheaded by O'Driscoll. But the Kinahans were just some of the many notorious drug dealers and criminals O'Driscoll successfully brought to book. During his tenure at Dublin's Store Street, he was tasked with reckoning with the heroin epidemic, and his unique approach to community policing got to the root of the power of infamous criminals like Tony Felloni, Michael Cronin and Derek Dunne, stripping them of their assets. Spanning a period of unprecedented change that challenged the very nature of fighting crime in Ireland, On Duty, the first ever memoir of an Assistant Garda Commissioner, offers a unique insight into policing at the highest level.