All this time has passed — you have changed jobs; been on holiday twice; got married; had children; been to war with Iraq; tried the Atkins diet — and the next time you lay eyes on Matthew Macfadyen’s Tom Quinn, MI5 agent, he is exactly where he was the last time you saw him; which was standing outside his fortress of a house, unable to prise open the high-security door, trying to get his girlfriend and her daughter out before an IRA bomb detonates. Then, bang! Then silence. They don’t write; they don’t phone. Now, suddenly, they’re back.

The explosive cliff-hanger was a clever way to end the first series; and a tricksy way to start the new one. Because the explosion we saw turned out not to have been at the scene we had been focusing on for the previous few minutes. You see, it wasn’t Tom’s house in North London, with his girlfriend trapped inside. It was the house of the Northern Ireland Secretary in South London. That is who the IRA were aiming for all along.

Spooks managed to get away with this deception largely because the writers had already shown us that they had no qualms about ditching prominent characters when, in only the second episode, the agent played by Lisa Faulkner was dunked into a deep-fat fryer. So maybe Tom’s girlfriend, too, would be sacrificed in order to show us that we should continue to expect the unexpected. What the writers hadn’t taken into account was that Tom’s girlfriend is such a morose presence that most viewers wouldn’t have wept to see her go anyway.

Not that Macfadyen is a bunch of laughs, either. Maybe it is just written into his contract that he is forbidden from breaking into any kind of smile throughout the series. Even if you can swallow all the other spy world fantasy in Spooks it remains hard to believe that MI5 staff never have a laugh about anything. Does laughing count as treasonable behaviour here? Even in The West Wing — from which Spooks seems to have borrowed a habit of filming Tom, Zoe (Keeley Hawes) and Danny (David Oyelowo) holding conversations while criss-crossing the corridors of MI5’s plush headquarters — the White House staff crack jokes occasionally while they tweak the fate of the world.

The makers of Spooks have borrowed some of the gadgetry from Bond movies (this week we had bugged cufflinks that were able to decipher the computer key-strokes being typed by a terrorist) but have carefully borrowed none of the double-entendre one-liners.

Where Spooks also distances itself from the Bond franchise is that its baddies are not cat-stroking megalomaniacs plotting to take over the world from the safety of their subterranean headquarters; they are characters recognisable from contemporary newspaper headlines — dodgy IRA informers; east European terrorists; and, next week, Islamic fundamentalist preachers in Britain who incite young Muslims to become suicide bombers.

The one moment of Bond-style self-referential knowingness came in a video rental shop when a Serbian agent who is under surveillance picks up a video and reads its title before tossing it aside, explaining that: “I’m not a fan of spy stories. They always make espionage seem so exciting. And if you ask me, it’s probably quite the opposite. The actual job, I mean.”

This truth is the weakness of most spy stories on television or in movies. It is hard to make exciting television about the genuine lives of MI5 staff, when most of them do jobs no more life-threatening than monitoring the output of radio stations in countries you have never heard of, or listening to thousands of hours of crackly telephone traffic on the off-chance of hearing the words bin Laden. Most jobs are more humdrum than they are depicted on TV, and that goes for journalists, politicians, lawyers, private investigators, and even rock stars.

It goes for soldiering, too, as we heard in The War We Never Saw: Virgin Soldiers (Channel 4), in which the military film-maker Dodge Billingsley trailed a group of US soldiers in Kuwait — India Company, 3rd Battalion, 7th Marine Regiment — as they prepared for frontline action in the recent invasion of Iraq. For many of them it was their first taste of combat.

“Hollywood’s like really messed us up,” one soldier told Billingsley, having quickly noticed that war was nothing like you see in Rambo or Schwarzenegger films. “They should make war movies six hours long with 15 minutes of fighting scenes. And the rest just sitting around, throwing rocks; that’s what war is.”

Having watched The Laziest Men in Britain (ITV1), I find that I just can’t be bothered to write about it. Though I wouldn’t necessarily take that as a compliment.

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