The description “criminal barrister” is normally used to mean a barrister who specialises in criminal law, rather than a barrister who is also in fact a criminal. But then William Travers is an unusual barrister in many ways.

Though formerly a member of London chambers, he now seems to be a partner in a provincial firm of solicitors in Ipswich. His office is neat and tidy and contains no law books apart from half a shelf randomly filled with a few odd volumes of Halsbury’s Laws and Statutes. Neither there, nor in court, nor at home do we see him with the criminal practitioner’s bible of choice (be it Archbold or Blackstone’s). Even if the plot does not call for their use, the idea of a lawyer working without access to law books or law reports seems, let us say, far fetched.

But then Travers is an unusual barrister. He asks his clients point-blank whether they are innocent. “Did you kill her?” It’s not a question defence counsel normally asks, because the answer may prove professionally embarrassing. But Travers is different. He won’t defend them unless they swear they didn’t do it. Only then can he give of his services. And he’s good, he’s one of the best. As someone remarks, no one “does murder” like Travers. He gets them off. Trouble is, what happens if they turn out to have been lying? What happens if they did, after all, do it?

Well, as has been noted, there’s no one who “does murder” quite like Travers. And that’s the point of this somewhat drawn-out mystery psychodrama, written by Anthony Horowitz, on which ITV lavished all its best production values (apart from a set of The Law Reports) over a five-day mini-series aired last week. Injustice is based on the premise of a barrister who is so haunted by the consequences of his role in the administration of what turns out to have been an injustice, that he takes the law into his own hands and declares himself judge, jury and willing executioner.

Part ghost story, part thriller and part just good old fashioned cat-and-mouse detective yarn, Injustice was certainly ambitious. It took in animal rights terrorism, youth detention, ruthless (sometimes lawless) police detective work, toxic capitalism, investigative journalism, arms dealing, domestic violence and, up to a point, the law. There were two murders, a suicide and what was probably an accidental death. A heady mix which, despite the time lavished on it, didn’t quite come off.

In re Silk [2011] BBC 1, applied.

It got off to a bad start by appearing to treat the recent BBC law drama, Silk, as a binding precedent, and duly applying it. First there were the blood-red threads that twisted and turned across the screen over the opening credits, to the urgent rasp of an ascending cello, so reminiscent of the unravelling pink tape over the credits for Silk. Then there was the opening court scene, in which Travers successfully defended someone who, just like the defendant in the opening court scene in Silk, was alleged to have burgled an ex military man’s home and stolen his much-prized service medal. In Silk, it became clear after his acquittal that the client in question was after all guilty. In Injustice, it turns out to be a different client who pulled the wool over his own brief’s eyes. But the solution proposed in Silk – report the matter to the police – doesn’t meet with Travers’s approval. He doesn’t think much of the police, who take the law (or at least the evidence) into their own hands. So he decides to, er, take the law into his own hands. Or rather – and this really the point of the whole story – not the law, but justice.

It’s an arresting idea, which was somewhat marred in the execution. Vigilantism has not had the literary or filmic treatment it deserves. In fact it has generally had little better than a lurid pulping, as in The Four Just Men by Edgar Wallace (1904) and I, The Jury by Mickey Spillane (1947) both of which became films, along with Death Wish (in which director Michael Winner at least refrained from telling the Charles Bronson character to “calm down dear” as he went on a righteous rampage against all the city’s crooks and hoodlums).

In Horowitz’s hands, the vigilantism idea takes on a more subtle psychological flavour. Travers (played by James Purefoy, with a somewhat wooden choice of three frowns – angry, puzzled, or mildly amused) has had a nervous breakdown after being confronted with the duplicity of an earlier client, an animal rights activist who put a booby trap bomb in the car of a scientist who experimented on animals. The scientist’s schoolboy son was killed when the car blew up but Travers got the suspect off. When he realised the truth, he couldn’t square it with his conscience and gave up his successful London practice and went to live in the country, where his wife (Dirvla Kirwan) yearns for her old metropolitan publishing work, and makes do with teaching Eng Lit (eg George Orwell’s Animal Farm) to bolshy inmates at a young offender institution. When Travers spots the former client on a railway station, he follows him and discovers the abandoned farmhouse where he’s been hiding out. When, later, the man’s body is discovered, a bullet hole through his head, the detective reckons it’s been an “execution”.

Detective Sergeant Mark Wenborn is not a “nice” fellow. The niceties of the rules of evidence cut little ice with him, and section 76 of the Police and Criminal Evidence Act 1984 is a rule more honoured in the breach. But he “gets results” one way or another, in much the same way that Travers “does murder” in one way or another. Wenborn (played by Creed Miles) is a nasty piece of work, whose smile is even more scary than his snarl; but he is on the side of justice, just about: he is Right and Revolting (as 1066 And All That would say) where Travers is Wrong and Wromantic. Pitted against each other, they play out what becomes a dance of death.

Injustice can be seen on ITV Player for another three weeks or so.

STOP PRESS: more curious connections

1. Dirvla Kirwan, who plays Travers’s wife in Injustice, is actually married to the actor Rupert Penry-Jones, who plays one of the two rival barristers striving for Silk, a second series of which is apparently in the offing.

2. Anthony Horowitz, who wrote the screenplay of Injustice, has been asked to write a Sherlock Holmes “continuation” novel. It’s title? The House of Silk