She wrote: “Opening with a nerve-shredding set piece, an enigmatic central character and a fusillade of acronyms and police-speak (who or what is a chis? What’s the PNC? Is 1A on the matrix good or bad? I have precisely no idea, and that’s part of the fun), this had all the hallmarks of a classic Line of Duty opener, but never felt like a case of bent coppers-by-numbers.
