Don't miss a thing by getting the latest from the Manchester Evening News sent direct to your inbox Line of Duty made a much welcomed, and highly-anticipated, return to TV screens last weekend.
With the new series set 18 months since we last saw them, a lot of things have changed at AC-12. But our favourite characters - Superintendent Ted Hastings, Detective Sergeant Steve Arnott and Detective Inspector Kate Fleming - were all back, even if Kate has jumped over to the MIT.
What hasn't changed, however, is the frequent use of police acronyms - and there hasn't even been an intense interrogation scene yet.
Viewers were left baffled during episode one with the frequent use of CHIS. The acronym, which stands for Covert Human Intelligence
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