Spooks: The drama with more ghosts than most

Has there ever been a TV show as wilfully preposterous as Spooks? Has any other long-running series ever been so pitilessly dismissive, careless even, with its main characters? The creators regularly bump off these much-loved spies with brutish abandon. Buffy the Vampire Slayer sporadically bumped off a favourite character to spice things up – Giles's girlfriend, Jenny, most memorably – and The Sopranos, obviously, wasn't shy of assassinating a mobster now and then. But Spooks does it all the time. Imagine The Man from U.N.C.L.E.'s Napoleon Solo (Robert Vaughn) having his head deep fried (as Lisa Faulkner's Helen had in Spooks, in the first series, just two episodes in) one episode, while David McCallum's Illya Kuryakin is blown to smithereens the next. Or the Scooby Doo gang – Velma, Shaggy, Scooby himself – being systematically tortured one episode, and shot dead the next, as befell Miranda Raison's Jo in Spooks, series eight. Okay, these are silly comparisons, but Spooks is a supremely daft series. It makes 24 seem restrained.

Spooks, which is easing, with its usual manic blend of slickness, thuggishness and po-facedness, into its ninth series, zeroes in on a small, not terribly merry band of MI5 officers working in a laughter-free office known as The Grid. Their leader is the understandably downcast Sir Harry Pearce (the excellent Peter Firth), the only constant in this typhoon of insanity, upon whose hunched shoulders the safety of the UK befalls. He's head of MI5 and he makes the tough decisions. In the first episode of this new series he risked the lives of every Londoner with a pacemaker in order to safeguard the lives of thousands. Nine people with weak hearts eventually perished. His equally grim-faced colleague Ruth (Harry's great love and along with Harry the only survivor from the first two series) tells him it is okay, because their job's all "about numbers". The dialogue is absurd, the acting absurdly earnest, but it's also compelling; horribly compelling. You can't turn away for a second for fear that one of the new cast members will perish – the recent "old" ones have been dispatched with: Rupert Penry-Jones's Adam exploded, Hermione Norris's Ros Myers was similarly blown apart, Ben Kaplan's Alex had his throat cut by one of his own. It's breathtaking in its savagery. In recent times, only the trusty and brilliant geek Malcolm Wynn-Jones was permitted to walk off into the sunset, but only after he – obviously – had a shooter pointing at him in a suitably harrowing confrontation.

And what, for the love of god, is happening with MI5's vetting process? It is, frankly, shoddy. Our new rugged, square-jawed hero, Lucas North (Richard Armitage) isn't who he seems. He appears to be someone called John, as a shifty Iain Glen keeps on popping up to inform us. Surely someone at the vetting stage would have twigged this? I mean, security would have been tightened, surely, after Connie James (Series 7) was revealed to be a Russian sleeper agent and casually cut the quite dull Alex's throat, in the supposedly secure environment of The Grid.

Not many series would get away with this, and after poor, doe-eyed Jo and rock-hard secret agent Ros were disposed with, I didn't feel like "playing" any more. But their demises haven't stopped me tuning in. It might have something to do with the show's giddy breathlessness; the pace of these episodes is audacious, relentless, unhinged. You don't have time to grieve. There's always an impending crisis – a monumental crisis – and no one here has time to mull over the deaths of anyone, frankly. Harry threatened to quit in the first episode, bemoaning, "Does it ever stop, Ruth?", and if Harry's spymaster walks out, or is slaughtered, I really do think I'll stop playing. But I also told myself that about Adam, Ros, Jo, Danny, Tom, Zoe, Malcolm, Zaf... It seems that the Spooks juggernaut doesn't need any single character to keep it going. It really is a bizarre one-off.

'Spooks' is on Mondays at 9pm on BBC1