For thirty years, David McDonald was a prison officer in some of Ireland's most notorious institutions.
His baptism by fire was in Mountjoy in Dublin. A chaotic, pungent and overcrowded place, he experienced the primitive way in which order was kept, and spent over a year working with prisoners with AIDS who were treated in an appalling manner.

Next he transferred to Europe's most secure facility: Portlaoise. Guarding IRA subversives, and high-profile gang members and violent offenders known as the 'heavies' - including John Gilligan, Christy Kinahan, Brian Meehan, Dessie O'Hare and Graham Dwyer - he had to be ready for anything. Tackling rioters and foiling inventive contraband schemes were all in a day's work.

Promoted to Assistant Chief Officer in 2000 and transferred to the new Midlands Prison, he took charge of the protection wing where prisoners who are deemed to be at risk from other prisoners are housed. Yet the harshness of prison life and the myriad issues caused by drug addiction would leave him questioning what is often a brutal and inadequate system. Serious concerns about how some situations were handled led to McDonald becoming a thorn in the side of prison management. Ultimately his concerns led to him becoming a whistle-blower. Now, writing with award-winning journalist Mick Clifford, David describes in vivid detail the sheer power afforded to prison officers, and the vulnerability that comes with being outnumbered by inmates; the tension punctuated by extreme violence, and the human moments between inmates and officers. Unlocked is a jaw-dropping and authentic account of life in the toughest of workplaces.