This review contains major spoilers if you haven't seen the episode...

With a body count being racked up that would make Robocop impressed and chances of survival for members Grid being like that of a red shirts on a Star Trek away mission, the Spooks team's continual shift in character, and feeling that nobody is safe, shows that Spooks is one of the most compelling and addictive bits of television on at the moment.

We kick things off this week with a secret meeting of the world's movers and shakers. Oligarchs, oil barons, bankers and technologists have congregated in London for a meeting, and while these billionaires are ‘the real' people who run the globe, the government still have a presence there to protect these people, with Harry assigning Ros to work undercover to make sure that these money men are protected and the wealth and stability in the west is safe.

Although the meeting is ‘off the radar', a Russian delegate Leon Gevitsky has his niece Nina stopping with him while in London and, unknown to him, this wry and doting Nina is actually a mole and working to bring down her billionaire uncle from the inside, being the way in for a group of global-terrorists to find and eventually gatecrash the secret meeting.

Attacking the stately home the meeting is taking place in, the terrorists round up billionaires at gunpoint and proceed to take their moneyed quarry into a secret panic room situated under the meeting place.

With Ros deep undercover, the eco-terrorist group consists of a highly educated French militant, Finn Lambert,  his lover, (the aforementioned Nina) and his ‘partner in crime', Rudy, whose computer genius has even Grid member Tariq impressed with h is technical and cunning computer expertise.

With the world's elite rounded up ,the terrorists' plant bombs throughout the panic room and proceed to set up a mock trial, broadcasting the trial via webcams onto the Internet.

The trial's streamed live, conducted by Lambert who, thanks to his own legwork, Rudy's hacking skills and a mysterious backer, takes each billionaire in front of the camera, accusing each (in may cases rightly) of atrocities, crimes against humanity and disregard for law.

In the ultimate case of audience participation and voting, Lambert broadcasts to the viewing public that it is up to them to play judge, jury and executioner to the hostages, allowing the viewers to vote yes or no to whether the crimes put across by him against his captive are so heinous that the only way to provide justice is execute them there and then, live online.

With the first trial's verdict giving the first billionaire the thumbs down, he is brutally executed live online and with neither Jo or Lucas (who are onsite above the panic room) being able to do anything about it, it's up to Ruth, Tariq and Harry back at base to, once again, make those tough decisions.

With the second trial about to begin, Harry is contacted by the Home Secretary stating that his CIA counterpart wants the situation stopped as not only is it bad for PR and relations with the Middle East but also, by exposing these billionaires on trial, numerous secrets and deals that Americans do not want public could be aired.

While the home secretary is reluctant to agree, aspects of national security might be at stake and, as such, signs up to storm the panic room with the intention of nobody getting out alive.

While this protocol seemed a little harsh, on reflection, it seemed the best thing to do as Harry finds that the CIA's intention is to be all American and to smash things as hard as they can in a proposed air strike on the stately home (nuke it from orbit, it's the only way to make sure) without thinking through the consequences or civilian casualties.

With the team above tackling these weighty matters, Lucas is commissioned to track down the terrorist money, tracing it through the CIA to an oligarch who has been bankrolling the terrorists with the intention of picking up the pieces of the financial ruin that Russia and the Eastern Block counties will be in if the economic stability of the world is under pressure. Torturing the information out of him, Lucas gets the financer to call the hostage takers and to call off the executions.

While the heavy handed tactics are being used by Lucas, for once Ros is using the softly softly approach, slowing digging away at Nina, who is shocked at the brutality of the executions and is beginning to have doubts that she will not get out alive.

Ready to break, Nina releases the doors of the panic room allowing a negotiator to come down. However, the potential sacrificial lamb into the bomb filled situation is Jo, whose presence, combined with Nina panicking and Lucas pushing the bankroller to tell the terrorist to stop, ignites the situation with a fatal shootout taking place.

Needing to take out both the terrorists and the bombs, Ros kicks into action taking control and doing what needs to be done by taking out Lambert. But in doing so also tragicallytakes the life of Jo, who sacrifices herself to stop the bomb going off in the panic room that would kill everyone.

With Jo slowly dying and the team on the ground in shock, the day is saved, as we cut back to Grid HQ. As Harry and Ruth hear  the news, we cut to black as, once agai,n the Spooks team lose another member.

Shocking, unexpected and nail biting to the extreme, Jo's death is completely unexpected in this fantastic, if tragic episode and, once again, proves that Spooks is by far one of the best British shows on at the moment. Absolutely cracking stuff.

Read our review of episode 2 here.

Spooks airs on Wednesdays at 9pm on BBC One and Thursdays at 12:15am on BBC Three.