Vigil:In A Wilderness Of Mirrors.

"But we're not at war" - Chief Inspector Amy Silva

"That is an illusion. We've always been at war" - Commander Neil Newsome

Blimey. Vigil (BBC1/iPlayer) was confusing. A very well made, and well acted, drama, it had so many characters and so many competing, overlapping, storylines that it was hard to get a grip on it - and even harder, for the most part, to emotionally invest in it. Unlike Line of Duty, the show to which it has been most regularly compared, all the disparate strands resolutely refused to coalesce as neatly or dynamically as an engaged viewer would wish.

Which was a pity as Vigil was not without its moments. How could a drama featuring murder, international espionage, industrial sabotage, adultery, and intrigue on a submarine not be? Not least when the Russians, Americans, and Chinese are brought into a tale that involves peace camps, drugs, spies, and shadowy men and women carrying out shadowy activities hundreds of metres below sea level in a defiantly enclosed space.

A friend of mine, let's call him Adam - because that's his name, was not impressed from the start. He'd not been a fan of Line of Duty and Vigil, to him, was Line of Duty on a submarine. Not only that, he was adamant that the submarine in Vigil was way bigger than any genuine submarine in real life. I don't even know if that's true (I've never been on a submarine) but I'm not totally sure if that's particularly important.

His first criticism held more weight. Not least because Vigil begins with the death, a suspected murder, of Chief Petty Officer Craig Burke and Burke is played by Martin Compston who is of course best known as Steve Arnott in Line of Duty. This time Greenock born Compston gets to play a Scottish character but it is the Scottish landscape, the mountains, the lochs, and, more than anything else, the wide open sea, that makes Vigil a visual delight.

Even the grey industrial naval blase looks great and the HMS Vigil, herself, looks like a plankton encrusted mega-cetacean as reimagined by H. R. Giger. What's going on inside the Vigil, however, is the heart of the drama and if the premise, Detective Chief Inspector Amy Silva (Suranne Jones) is sent on board the Vigil to solve the mystery of Burke's death and uncovers all manner of intrigue and misdeed - while at the same time suffering with anxiety, guilt, and even claustrophobia, is a little too conventionally tidy that should at least make for a compelling drama.

At times it does but there are certainly periods of longueurs in which, despite there being lots happening, I found my attention wandering. Burke's death is initially treated as a suspected heroin overdose but a cast of characters lead Silva to come to a very different conclusion. Not least due to the suspicious, and often unwelcoming, behaviour she witnesses on the Vigil.

Commander Neil Newsome (Paterson Joseph) is insistent that the Vigil is a vital nuclear deterrent and must, at all times, remain effective. He's not keen on Silva's perceived threat to his leadership, it brings out some 'behaviour' in him, but she's hardly the only one who is undermining him. Lieutenant Commander Mark Prentice (Adam James) doesn't respect Newsome's leadership and thinks he's a 'prick'. 

Prentice is even more defensive in his dealings with Silva. Chief Petty Officer Gary Walsh (Daniel Portman) appears to be a violent drunk, two other Chief Petty Officers, Tara Kierly (Lois Chimimba) and Matthew Doward (Lorne MacFadyen), never seem too far from insubordination and Surgeon Lieutenant Tiffany Docherty (Anjli Mohindra) is obviously nursing a secret she doesn't want Silva to discover. 

Lieutenant Simon Hadlow (Connor Swindells), at least, seems to respect his seniors and carry out his orders properly and the coxswain Elliot Glover (Shaun Evans) is the one crew member who, initially at least, seems eager to help Silva in her work. Quite an asset for a woman on an almost entirely male ship, sorry - boat, that is underwater and out of view.

As Silva's time on Vigil is, predictably, extended, as she treats her anxiety issues with meds (her usual option of running, of course, not possible on a submarine), and as we see flashback's earlier life (idyllic, but clearly heading for serious trouble), we see Prentice get nastier and angrier. To the degree that he must, surely, be a red herring? 

Will his attitude towards Silva cloud or impair her judgement of him or is he just the start of a much bigger story? Images of Vladimir Putin in the opening credits suggest so. The trademark suspicious glances between characters you find in this kind of series confirm it. And as we jump, jarringly, from roadblocks, portakabins, the playing out of hierarchical enmities, and Silva being subjected to various discomforts and tortures to scenes of awesome seas and romantic trysts in bathtubs it all gets a bit confusing.

MI5 get involved although it's not always easy to tell exactly why, poignant silences give way to lengthy scenes of bureaucratic showdowns in bland corporate offices, there's a blast of The Walker Brothers My Ship Is Coming In, a haunting theme by Agnes Obel, and there are folk songs about and references to the Stornoway tragedy of 1919. It paints quite a picture but not always a clear one.

There's a lot of cop vs navy and plenty of cop vs cop and navy vs navy too. Up periscope, and back on the Scottish mainland, Silva's ex-partner Detective Sergeant Kirsten Longacre (Rose Leslie), under the aegis of Detective Superintendent Colin Robertson (Gary Lewis), has been enlisted by Silva to tie up littoral loose ends and uncovers more than she bargained for when she runs into the peace protestors Jade Antoniak (Lauren Lyle) and Ben Oakley (Cal MacAninch).

As Silva and Longacre's back story, as well as that of many of the other key players, starts to unravel, we begin to realise there is a huge, and very nasty, conspiracy being uncovered. Where Vigil works best is in the deliberate ambiguity it places in our minds as to what each and every characters involvement, or not, in that conspiracy is. For that, I give series creator Tom Edge and director James Strong a lot of credit.

Ideally, however, the makers of Vigil could have cut about an hour of its running time and culled a few of its minor characters. Then they would have had a drama that sped through the waters of television as sleekly, as speedily, and as effectively as a fully functional submarine. Perhaps it was apt that Vigil, like the HMS Vigil for which it was named, took on too much water and at times nearly sank under the weight of its ambition.