'Another wild bath night in Aberystwyth.'

That's the deadpan line DCI Tom Mathias delivers upon visiting the rural crime scene and finding the bath filled with blood. Yes, this is Welsh noir.

But the very novelty of 'Welsh noir' wasn't enough to charm me and I sat down to watch BBC4's Hinterland with a sigh and a grumble of 'not another crime drama!'

My suspicion that Hinterland was going to be just another tired and self-consciously 'gritty' cop show was ruffled further when the victim was revealed to be a female and when the well-worn line was uttered which must occur in every crime drama: there was no sign of forced entry so she must have known her assailant! In the next session of Parliament legislation will be introduced to make it compulsory to have that line in every cop drama.

With that old chestnut having been delivered I was now watching the clock and regretting that this show, a full-length drama, was one hour and 35 minutes long.

But then things perked up considerably. Hinterland veered away from the typical scenes of grizzled, smoky cops in dingy interrogation rooms and went all melodramatic. It began operating in the language of Victorian Sensation fiction and introduced an abandoned children's home, dusty attics, a battered tin box rattling with pulled teeth, all set in a brooding, sinister place called Devil's Bridge. These satisfying Gothic touches hauled it a thousand miles away from the standard crime dramas and I started to enjoy the story.

The plot began simple: blood and wreckage had been discovered in an old woman's house. Soon enough, they find her battered body and it is that of Helen Jenkins. She has been dumped in a ravine beside the old Devil's Bridge children's home. Detective work reveals she used to be the owner of the home and, as the police start tracing former residents, they discover each child had loathed her. She was spectacularly cruel to them: pulling their teeth with pliers and sending them to 'the hard room' for punishment. A race then begins to determine who hated her most, and who suffered the worst at her hands.

The plot finally resolves itself in unashamed Gothic melodrama in an old country church, amidst scissors and screams and tears. Yes, it was all rather garish and overblown but it was vastly enjoyable and the denouement even drew a little whimper of shock from me.

Next week's episode of Hinterland will see the team tackle a new investigation but it's hard to see how they can top the opening week's storyline for good, honest drama. However, I hope they do as it was the mad stampede of the plot which set this show apart from the crowd and it'll need to be strong to stay apart because crime dramas are becoming ever more ubiquitous. Yet another one starts on Tuesday - Happy Valley on BBC1 - and I wonder why. Are police stations the only venues in this country in which drama occurs? Hardly. Think of the trauma and horror a social worker must see in their job, so why is there no infinite parade of dramas set in social work departments? Probably because there's no glamour in seeing stressed and exhausted women at work, doing overtime and filling out paperwork. We apparently want cops in sharp suits and fast cars who occasionally stop said fast cars to have sex with one another.

That's why, even though I enjoyed Hinterland, when I saw it advertised I just shuddered and thought 'oh God, another one.'