Another (Un)pleasant Valley Sunday:Happy Valley S2.

Hammer attacks, blackmail, rape, murder (obviously), suicide, more rape - this time with broken beer bottles, drug overdoses, the trafficking of young Croatian women, men being tasered on their dicks, and people desperately buying scratchcards.

Happy Valley is, resolutely, not what I once thought it was. Because it aired on Sunday evenings, and because it starred Sarah Lancashire - as well as at least two other ex-Coronation Street actors, I'd imagined it to be some kind of feel good Sunday night drama that you could watch after your bath and before going up the wooden hill to Bedfordshire ready for school or work the next morning.

Ballykissangel, The Darling Buds of May, Last of the Summer Wine, that kind of thing. It is absolutely not like any of those shows and it is, most definitely, far better for that. It's tense, emotionally engaging, gripping, and, sometimes, it's shot through with paranoia and a sense of claustrophobia. There are twists galore and often you can't see them coming. As the second series moves into its final couple of episodes there are so many chills that no lesser an expert than John Travolta would have to agree "they're multiplying".

Series two of Happy Valley (BBC1/iPlayer, created & written by Sally Wainwright, and directed by Wainwright and Neasa Hardiman) first aired back in February and March of 2016 and it picks up, pretty much, where the first series ended. Or at least eighteen months after when Sergeant Catherine Cawood (Lancashire) find a dead body. The body turns out to be that of the mother of her arch nemesis Tommy Lee Royce (James Norton).

Tommy's mother, Lynn, has been raped and murdered. Tommy himself is in prison in Gravesend and he doesn't take the news well. He's also not happy that he's on the receiving end of a court order barring him from contacting Ryan (Rhys Connah), the child he fathered when he raped Catherine's daughter. Ryan's still living with his grandmother, Catherine, and her sister Clare (Siobhan Finneran).

Because of her history with Tommy, and because she'd phoned Lynn to warn her not to contact Ryan, Catherine is, initially, made a suspect but it soon becomes to look more likely that there's a serial killer on the loose. Especially when other dead women are found, having suffered the same terrible treatment.

The case is taken on by DI Jodie Shackleton (Katherine Kelly) and DSU Andy Shepherd (Vincent Franklin) and they're assisted in their work by DS John Wadsworth (Kevin Doyle). Wadsworth, however, struggles to keep his mind on the job. He's cheating on his wife Amanda (Julie Hesmondhalgh) with another woman and that woman, Vicky (Amelia Bullmore), is not the sort of person to give Wadsworth an easy life.

Nevison Gallagher's (George Costigan) daughter, Ann (Charlie Murphy) has joined the police and she has fallen under Catherine's wing. Ann's a police community support officer but she wants to become a detective and as such offers up some amateur and unsolicited, though impressively perceptive, sleuthing. She's the only one to cotton on that Wadsworth's having an affair but that still doesn't stop her arranging to meet him for a drink after work.

Ann's also prone to drinking heavily and is grieving the loss of her mother, Helen (Jill Baker). So too is Nevinson who, under stress, sacks under performing, apologetic, and often drunk employee Sean Balmforth (Matthew Lewis). Sean, as with so many people in Happy Valley, will soon find himself in serious trouble and, like Wadsworth - very much the Kevin of series two, completely out of his depth.

Things are changing for the Cawood family too. Catherine's son Daniel, now a father himself, (Karl Davies) has been thrown out by his wife and moves in with his mum. Daniel claims to be sad about the situation but angry seems a more accurate description of his mood. Although he does, at least, seem to be finally getting on, and building a relationship, with Ryan.

Clare, for her part, bumps into an old school friend, Neil Ackroyd (Con O'Neill), and, soon, a cautious romance is blossoming between the two of them. Both former alcoholics, there's a chance they'll understand each other's struggle - and a danger they'll enable each other. Neil's been through a pretty rough patch. He's gone through a divorce, had a breakdown, and lost his job at the building society. It's hard to know if he's still in that spiral or if he's getting better.

Despite being in prison, Tommy seems to have got a girlfriend. Frances (Shirley Henderson) visits him fortnightly. She's clearly smitten by him and she appears to be something of a wrong 'un herself. An opinion that only seems to be confirmed when she fakes a CV to get herself a job as a teaching assistant. At Ryan's school.

Elsewhere in Happy Valley, the usual minor crimes of sheep rustling and people taking acid continue but when simple minded sheep farmer Daryl Garrs (Robert Emms) becomes the victim of merciless bullying by a group of thugs it opens up a whole new storyline. One that soon completely overtakes both Daryl and his mother, Alison (Susan Lynch), and, of course - this is Happy Valley, becomes ever more relevant to what's happening elsewhere.

You're not far in to series two when you realise there are lots of questions to be answered and you find yourself eager to find out what those answers will be. Why is Ann drinking so much? Who gave Ryan such an expensive gift, a £149 Scalextric set, for his birthday? Is Neil keeping something from Clare? What does Frances see in Tommy and how far will she go to please him? And why don't we ever see any of the criminal Knezevic family?

Even more who will get killed next and, most of all, who is doing all the killing? Plenty of suspects are lined up but they can't be all guilty, surely? One of the joys of the show is that we know of at least one person's guilt from very early on and, for them, the sense of the net tightening around them is painfully palpable.

With shout outs to Angela Pleasence as Catherine's neighbour Winnie, Ivana Basic as the trafficked Ilinka, and Rick Warden as Inspector Mike Taylor (Catherine's boss who shows her respect while also, often, being infuriated by her), series two of Happy Valley is even better than the first series. Clare starts off being mainly used for exposition, over ciggies and cups of tea naturally, but soon gets a story worthy of an actor like Finneran, and if the scene where Catherine attends Lynn's mum's funeral (despite being suspected of her murder) seems a little far fetched then it's perhaps worth bearing in mind that Happy Valley doesn't let reality get in the way of telling a good story.

You go with it because it's such a thrilling ride. There are particularly emotional moments and two of these come in exchanges between parents and their grown up children. A heart to heart between Nevison and Ann the night before Helen's funeral and when Catherine passes a desolate Daniel an early morning cuppa and, with a sad look on her face, says to him "I wish I knew what was wrong with you".

There's something very wrong with a lot of the people in Happy Valley but there's nothing wrong at all with Happy Valley as a drama series. In the first episode of this series, we see a storm cloud looming over the valley. Meteorologically speaking, it's not seen again. Metaphorically, it completely refuses to budge for the entire duration of the series. Enjoy watching it. Be thankful you don't live in it.