Mercy O'Callaghan has been running from Belfast's past for years—changing names, cities, and sins—but the war she left behind refuses to stay buried. When a tin of old letters resurfaces and a shot echoes through a Donegal church, Mercy is dragged into a reckoning with the only two people who ever owned her heart: Saoirse "Ashling" Kelly, the girl who once fought beside her—and now hunts her—and Ethan Prescott, the MI5 agent sent to bring Mercy in...or put her down.

From rain-lashed safehouses to docks at dawn, Mercy and Ethan make a brutal bargain to survive the city that made them. But love is just another weapon, and Ashling knows exactly where to aim. As secrets burn and loyalties break, Mercy must decide which ghost she'll finally lay to rest—and which she'll choose to live with.

Crimson Mercy is a gritty, intoxicating blend of Irish noir, romantic suspense, and moral fallout—perfect for readers who love high heat, high stakes, and heroines who bite back.