The Loch review: there are no hidden depths in this ITV murder mystery

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ITV has promised that the loch will become a "character in its own right," which is probably a good thing because it surely has more depth than any of the other characters in this show (pun intended).

The body in the loch remains undiscovered in episode one, but the peace is soon broken in the small town of Lochanfoy when a local gay piano tutor meets a grisly end. And for "grisly end", read: "has his brain extracted from his skull through his nose, Ancient Egyptian-style, except he's still conscious". (Thankfully, the gruesome act takes place off-camera.) Also, a bunch of teens pull a prank and assemble the "Loch Ness monster" on the beach using gross scraps from the local abattoir – and by the time the police arrive the next morning, Nessie contains a human heart. Something is very wrong in Lochanfoy.

As a murder mystery, this Broadchurch-a-like drama sounds promising on paper. The Loch has been penned by none other than Stephen Brady, formerly of Fortitude, Vera and Silent Witness. It also stars The Missing's Laura Fraser as ambitious local detective Annie Redford tackling her first murder case, and the visiting police chief played by Siobhan Finneran who was so wonderfully horrible as lady's maid O'Brien in Downton Abbey.

And sure, the plot all sounds very exciting. But there's something rotten here, and it's not Nessie.

It's just that the characters are so... one dimensional. And the dialogue is so clunky. "Frank Smiley? No, no problem with that," says Finneran's character (and career woman) DCI Lauren Quigley when she's summoned from Glasgow to work with an old colleague in Lochanfoy.

But after hanging up the phone she shakes her head and sighs – aloud – "Frank Smiley". Who does that in real life? Who ACTUALLY shares their thoughts with an empty room after a phone conversation unless they're signposting? There's no subtlety here. A more confident drama would have let us pick up on the beef between Frank and Lauren by ourselves.

She's not the only character who comes out flat, which is a shame because in another drama this cast could probably flex its acting muscles a little more. You've got Shona McHugh as Annie's daughter Evie, for example, but she's a 'moody, troubled, sensitive' teenager straight from soapland. So are her buddies Kieran and Jonjo, who have each been assigned a secret burden: a seriously ill brother and bipolar disorder, respectively.

There are hints that each of the characters has something to hide, which of course they do, because this is a murder mystery and don't we know it. Local doctor Simon Marr is being very shifty at a vigil for the dead man, and why did he hand him a broken CD before his killing? What's the deal with the jogger who found the body?

But every time there's a clue or something suspicious, it's like it has been circled with a hundred arrows pointing to it.

And yet somehow The Loch manages to still be confusing, and not in the sense of "I don't know who the murderer is but I'm dying to find out". It's more like, "Who's that again?"

There are a ton of characters, and it's really hard to work out how they're all knitted together in this community. Wait a minute – the jogger guy... is he the teacher guy too? Who was in the pub with Annie? Are we meant to remember? Baffling.

Unsurprisingly it is hard to feel investment in any of this. Usually with a murder mystery you spend a week turning the clues over in your mind, evaluating the suspects, coming up with a theory before the next episode. But no.

In The Loch we're told by trendy forensic psychologist Blake Albrighton that the murderer must crave attention, but I'm sorry – I can't bring myself to be more than vaguely intrigued by the identity of this sadistic killer.