Ant may have Dec, and Sherlock has Watson, but if there’s one duo the world just wouldn’t be the same without, it’s Happy Valley’s Catherine Cawood and her sister, Clare. 

The pair have stuck together through thick and thin. And thick and thin covers a range of trauma from the suicide of a beloved daughter and niece to the psycho son-in-law from hell running your colleague over with a car.

Repeatedly.

Throughout series one Clare was there to support her sister, and remind her that every tragedy that befell the Calder Valley police force was to be celebrated as “an excuse to take your mind off Tommy Lee Royce”.

And she was also there to be a brilliant pain in Catherine’s behind, tipping Daniel’s mum off about her little dalliance just so she could figure out how many plates to put out for a party.

Series two has seen Clare excel, in both annoying and aiding her sibling. Add to that her convenient ignorance about police procedure – which allows Catherine to seamlessly explain more complex matters to viewers – and ability to balance out her sister’s severity, and you’ve got a match made in TV heaven.

Who else could correct Catherine's language – it's "stick that IN (not up!) your pipe and smoke it" – and live to tell the tale?

From blazing rows to beautiful one-on-ones, these two simply ooze the kind of chemistry TV pairings can only dream about. They are, as tweeters might put it, #relationshipgoals and #squadgoals rolled into one.

Watching them sit back and shoot the breeze during the series two opener, I wanted nothing more than to be in their gang. And when Clare crumbled in her sister’s absence at Ann’s mother’s funeral, falling off the wagon and shoving a desperate Catherine aside, something inside me cracked.

They’re only fictional characters, though. "Why would you crack?" I hear you ask.

Because Sarah Lancashire and Siobhan Finneran have taken Sally Wainwright’s brilliantly written siblings and done something very special: made us forget Sarah and Siobhan, and fully invest in Catherine and Clare.

And without that wonderful pairing, Happy Valley would be anything but joyful.