Catch up with Line of Duty episode 3 via BBC iPlayer for the next 30 days.
DS Steve Arnott believes there is a dark secret in Danny Waldron’s past. But while DI Cottan is commended for cracking the Waldron case, the spotlight falls on Arnott’s questionable conduct in a previous enquiry.
Episode 4 airs Thursday 14 April at 9PM on BBC Two. Get a sneak peek.
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Daniel Mays 