As ever, nothing is wasted; not a scene, not a line, not a beat. For every morsel of information gathered by the team and by the viewer, another turn reveals 100 hidden possibilities. It fits together flawlessly.

Duty returns with a taut, screw-turning examination of an undercover officer gone rogue--the kind of slow-burn drama that earns your devotion. [17/24 May 2019, p.90]

It still holds up as a compelling story, even if you're missing the myriad call-back references from the first four seasons. ... It's a testament to Mercurio that just when you think, "Well, this person is clearly guilty, as all the evidence suggests," he's got multiple switch-backs and loopholes to play with.

If the new season falls slightly short of the show’s usual standard, it’s because neither this character (this season’s antagonist) nor the performance in the role is as interesting as its predecessors. Otherwise, all the elements are in place.

Much like in Bodyguard, a jolting twist at the season's midpoint changes everything, and what initially seemed like solid and smartly done procedural becomes urgent, must-finish-now TV. [13-26 May 2019, p.11]

My wife has been watching for 5 years. I started this last season (5). The series seemed decent up to the last 15 minutes of the last episode. I have never seen such an insipid wrap up twisting everything so artificially - so bad that once it started, I was telling my wife what was going to happen and it did. Utterly brainless garbage. The writer, director, and production people who approved this nonsense should be sh.t and p.ssed on.