If you were looking for relaxing television last night, the equivalent of hot chocolate and lavender, then the stimulating Spooks (BBC One, 9pm) was a bad choice.

It had more twists and turns than Chubby Checker and The Fat Boys put together.

"They're just watching and waiting. They've got the phones, security cameras, web cams, secure coms, e-mails – everything," says a rather tormented Tariq to Ruth.

The Grid has been compromised. Their computer systems have been hacked into by suspected Russian and Chinese hackers, and they can see and hear every move MI5 make.

When they turn power off, the team has just one minute and 40 seconds to formulate a plan of action. That's a lifetime in Spooks though.

You require a need for speed and a certain amount of intelligence to watch this superb spy drama.

Decide for yourself whether you qualify.

Or just watch the actors, like the handsomely brooding Lucas North, played by Leicestershire's finest, Richard Armitage.

A plot summary: Relations between MI5 and the CIA are already fraught. Harry Pearce agrees Section D and the rest of MI5 will use the USA's security system, Cybershell, to avoid further security breaches.

Lucas is tasked with protecting ex-hacker-turned-White-House-cryptographer Daniella Ortiz.

She has the codes to start Cybershell and Lucas must ensure her safe delivery to MI5.

So Cybershell is the hackers' prime target. They're going to use their own cryptographer while The Grid is powerless.

If they succeed, Russia and China will have unlimited access to MI5 and the CIA's entire catalogue of intelligence. I think.

"We have to shut down the hackers, no matter the cost to us," says a usually unflappable Harry.

So Lucas compromises himself, and that rather distraught Daniella character, AND his career to get the mystery Albany file. It's quite painful to watch. I actually found myself shouting "don't do it" at the TV.

The hackers are pretty smart. They call Lucas, and using a synthesized copy of Harry's voice, tell him to abort the mission and kill Daniella.

Lucas hasn't completely lost it. He knows something's up and calls Harry back. "What's your favourite opera Harry?" he asks. The line is silent, then the orders reiterated, emotionlessly.

So, he bungs Daniella in the boot, she gets shot in the neck during the great escape, and as she's later dying in his arms, we see his sinister selfish side.

But all's well that ends well for British Security Services. Harry hacks the hackers, and the boys are sent in. Lucas on the other hand is not so good. He's a man on the edge. And Ruth's on to him.