• Warning: Spoilers
    In an innovation on the prison city, a wing called Emerald City is created with Oswald State Penitentiary. With this wing prisoners are given more responsibility and better conditions. Sleeping two to a pod, with clean facilities etc. However the prisoners are no different and violence and crime runs the prison. No one is above corruption and murder can come from the smallest events. Drugs, rape and torture are weapons and no one is above betrayal and deceit as powerful partnerships are formed and broken.

    Insomnia can be a wonderful thing. I started watching Oz many years ago on Channel 4's `Later' slot in the UK. I used to watch Homicide: Life on the Street and they relegated it to a 1am slot. Because I couldn't sleep I used to stay up and watch it. Oz was on after this and I got into that. At first I couldn't believe how brutal it was then I got totally sucked in.

    I'm on the fourth series now and am glad I started watching it. The series has one major strength – the writing. The plot is one of constant tension and drama as plan follows plan follows murder follows betrayal etc. The storylines are always good and always brutal. However one of the main drivers for me are the characters. They change with time – they develop with events, they get killed – regardless of status within the series, they get killed!

    The best example of what I mean can be seen in just a few examples – but on the whole it's true of most of the characters. Beecher came into the prison as a normal guy jailed for drunk driving and killing a child. The abuse he got from Schillinger has completed changed him – in fact 4 series on he continues to change. Schillinger himself is compelling, despite being relatively one dimensional he is a powerful character. My `favourite' character is Simon Adebisi. In series two he became very passive, very submissive but it was revealed as an act and he has become his cruel manipulative self again. I could list them all – obviously there's going to be characters who come and go, background extras who have only a few lines to say, or who move the plot along by getting killed etc. but most characters develop or play major roles.

    In terms of actors the cast is mainly bit part players with no major lead roles under their belts, but to a man they all do good jobs when called upon. It's hard to pick out any one actor who stands out as it depends on their characters, but it's worth acknowledging a few. Tergesen (Beecher) has shone simply in the way he has convincingly changed his character over the years. Likewise Adewale Akinnuoye-Agbaje has done great work as the monstrous Simon Adebisi. These standout because they have shown how they can deal with extreme changes in their roles, however every other member of cast is totally convincing. J.K. Simmons will only ever be Schillinger to me after this and a bit part black actor from the UK's `The Bill' shines in the role of Said (Walker). I could fill this site with praise for the cast.

    The programme is clever and intelligent (although many can't get past the brutality, violence and swearing). The portrayal of the prison as not so much an integrated melting pot of races but a mixed room of races that all manage themselves first – much more like the real America. The use of the brilliant Harold Perrineau Jnr as a character and as a sort of street theatre narrator is certainly different and allows each show to make a social point or a commentary without being preachy is really good – and often funny too.

    It does of course have weaknesses. Sometimes the brutality can be wearing and be too much. Where they constantly bring in new characters each week just to kill them in the same show to move the plot along it gets a bit tired too – however this doesn't happen every week. The plots themselves can only go so far – basically they all come down to violence and betrayal in some form. My hope is that they will only make this for another series at most. It's better if they end on a high rather than risking showing signs of fatigue or running out of new ideas.

    Overall it's brutal, cruel, disturbing, violent and upsetting. Why watch then? Because it's very well written and made, it totally compelling, it has great actors and the storylines are rarely less than gripping. It has an energy unlike anything else – like a car crash, you don't always want to see what's happening but you can't help but look. After all isn't this how prison is? Superb television but not to everyone's taste.