As Sally Wainwright’s masterful Yorkshire noir approaches the end of its third and final series – and Sarah Lancashire’s heroic Sergeant Catherine Cawood her long overdue retirement – it’s worth savouring every episode.

Obsessed with... Happy Valley is the BBC’s companion podcast, in which comedians Amy Gledhill and Isy Suttie discuss the drama episode by episode. From the start, Wainwright begins to weave several narrative strands, so there is plenty to pore over.

Catherine’s teenage grandson, Ryan, is squabbling with his PE teacher, who, in turn, is abusing his wife, while a pharmacist-turned drug dealer is in over his head. Meanwhile, a body in a barrel leads Catherine right back to her nemesis, Tommy Lee Royce (Ryan’s biological father), who has recently transferred to a prison close to home.

As Gledhill and Suttie repeatedly remind us, Wainwright’s writing is all killer, no filler. While the same can’t be said of the podcast, they do make some worthy observations.

Tommy’s new mane and Spanish lessons hint at an escape plan, while the double mention of the necessity for double-declutching in the truck Catherine borrows from Alison to stalk Clare, Neil and Ryan on their secretive visit to Tommy could very well be a case of “Chekhov’s clutch” – like the writer’s principle of “Chekhov’s gun”.

As comedians, Gledhill and Suttie are well equipped to find comedy in the tragedy. When they bring up the devastating phone call Catherine makes to Clare, having caught her sister red-handed on the aforementioned visit, they take note of the triangular sandwich Clare is eating: “You couldn’t go and have a three-course meal while you were betraying your sister like that, could you?”

The laughs are much needed, given that Happy Valley is anything but happy, and you find yourself needing a breather from its overwhelming bleakness. However brilliantly bleak it is.

Listen to the podcast on BBC Sounds.