After last week's episode, which was probably the best piece of TV we have seen all year, we have finally reached the finale of series two of Ashes To Ashes. Was it worth the wait? Oh yes, indeed, but before I rush headlong into just how good the episode was, it's worth a little recap as to how we got here.

With Alex on the verge of returning to the ‘real world' and the future (or present version, depending on how you look at it) Summers goading her to become part of ‘Operation Rose', she is in a dilemma. If she wants to return home and see her daughter Molly again she must become the thing she hates, a corrupt police officer. With this thought we find that she has been recording her issues down on tape, and while this is incriminating (and a bit of a bolt-on plot device) it all seems very much in character with somebody who has to analyse everything.

In turmoil about her predicament she has visions via the TV of Gene Hunt reading her life story on Jackanory, in which she is also given the facts that her condition is critical in hospital as the infection she has caught (from removing the bullet last week) is spreading. It is only with a dosage of intense drugs that she will be able to awake from her coma. This idea of the countdown to the 50mls of drugs being administered gives a stark warning that if she doesn't find and solve the issues surrounding Operation Rose before the last resort drugs are finally used, then she will be stuck in 1982 forever.

Alex isn't the only one in conflict as, after last week's showdown with Chris, the team and Gene are treating the naïve policeman with kid gloves, leaving him out of investigations, alienating him from conversations and also the banter of the office. Even when Ray tucks into a battered piece of evidence at a chip shop crime scene, Chris is left out of the jokes (and they're good jokes, too). With his relationship with Shaz strained and feeling like Kurt Russell in The Thing, he is looking for any opportunity to redeem himself.

When this does occur, however, things don't go to plan. As we found out last week, Chris' implication with Operation Rose goes a lot deeper than is known. Rose, it seems, is an ‘inside job' designed and put together by a set of corrupt policemen who have been manipulating events both within the police force and criminal fraternity. Following up a grizzly murder with Jenette, a potential love interest for Gene (she's a baddie, you can tell), and her thug-like brother ‘Tiny Tim' (a criminal known for his violent nature who himself is scared of the implications in Operation Rose), Gene, Ray and Alex uncover a complex plot involving a bullion heist and a conspiracy that goes right to the top.

However, Operation Rose really is not quite as sinister as first thought. Although corrupt policemen are involved, the entire operation is nothing more than an elaborate robbery which at first would seem a bit anti-climatic.

While making for a good shootout finale, the concept that Summers, the Masons and the secret meetings and corruption are only really to do with money would seem a little disappointing. However, looking at the way the episode played out and the ‘pay-off' to the series shows the entire operation really is just a plot device. As Summers, it seems, is not really the ‘bad-guy' after all.

All series he has been portrayed as a devil, tempting Alex to the quick and easy route home. However, his continual testing of her loyalty to the police and especially to Gene, going as far as to plant her tapes of suspicion and thoughts in his office, are all designed to see just how incorruptible she is. Even when she is at direct odds with Gene, confessing to him her situation, she still doesn't crack, allowing Summers to get what he wanted from her, a way out and redemption for what he did in the past. For he was once in Chris' position - a corrupt police officer who turned a blind eye to what happened and was eaten away by guilt.

This pay-off once again works perfectly, much in the same way that Alex was unable to change history last season by failing to rescue her parents, Summers' story has weeded its way through the entire series, tempting Alex to believe that finding him out will be her ticket home, allowing her to ‘Quantum Leap' back into the real world.

Continually reminded by alarm clocks, posters, street signs and even crisp packets of her impending fate, Alex's final confrontation with Summers would seem to be the way home. But when she, Gene and Summers finally meet in a showdown it's heart-breaking, as she stands waiting and nothing happens.

Her disappointment is palatable as she gets hit by the realisation that finally bringing down Summers is not the trigger for her release. However, she doesn't have long to get upset as Jenette (in a twist that, frankly, was telegraphed miles away) shows her true colours, betrays Gene, holding Alex hostage at gun-point.

Gene, it seems, has, in turn, double-crossed her as we find that the incorruptible Gene has been using his nonce-bashing ways to find out all he could about the heist from her (as well as having a good time in doing so) and not vice-versa. And in this final showdown things do not go so well as Gene fires, missing his target, hitting Alex instead.

With this trigger it seems that this is the final action to send Alex home. Waking up in hospital in the modern day everything seems fine. Molly is there, it's 2008 again and the infection is gone. However, in the final pay-off of the series, and in a Twilight Zone-like dream within a dream sequence, things are not as they should be as it seems Alex is now in a coma in 1982, dreaming that she is in 2008.

Seeing Gene's face on ever monitor, television or electrical device is a nightmare and worthy of any Hollywood film twist. Not since the end of Blake's 7 has there been a finale to a show on British TV that has been this powerful. Gripping, terrifying and so obvious at the same time, this cliff-hanger with a potential series three in mind also takes us to a nightmare place that wants to find out so much more.

Again the writers of the show provide us with an episode that can go down as one of the best written pieces of TV we have seen for a long time. Ashley Pharoah and co. should be proud that not only has Ashes To Ashes surpassed Life On Mars (and in turn its own fantastic finale) but also managed to beat the heart-stopping finale of last series. Great, great stuff.

Check out our review of episode 7 here.