There are two things we're interested in after
Line of Duty episode four: nicking bent coppers and finding out who Joanne Davidson is related to. As well as prompting Ted Hastings' iconic "Mother of God" catchphrase, the 'reveal' that Kelly Macdonald's Davidson is the relative of [insert guess here] left our jaws on the floor.
However, with the show's fandom offering up its own identity parade of potential people behind the DNA match, viewers think they've just discounted a major name.
While Jed Mercurio has proven to be the master of bringing back familiar faces thanks to the return of Kettle Prison Guard #1, season five's Lee Banks and season four's Jimmy Lakewell, the confirmation that Jo is related to someone we already know is sure to signal a major blast from the past.