We’re not safe. That’s what Jed Mercurio thrillers have been telling us for years. The institutions there to protect us—hospitals, the police—are only as dependable as the people in them. And people, according to Mercurio’s dramas, are fragile. Greedy and arrogant, or damaged and under pressure, our protectors don’t always act in our best interest. Jed Mercurio’s Bodies and Line Of Duty gave us incompetent surgeons and bent coppers; Bodyguard gives us a personal protection officer who wants to put a bullet in the head of the person he’s been charged with personally protecting. A former soldier and current operational firearms commander with special protection, Budd is trained to take charge, shoot guns, and say things like “operational firearms commander with special protection”. He says it in the opening minutes of this episode to a train guard who’s called upon to do more than the usual railcard checks and station announcements when it’s discovered that there’s a terrorist bomber on the train. Ten minutes in, we see Budd follow a sense of moral right over the command hierarchy. He’s willing to put himself in danger to protect a stranger, and having lost friends on tours of Helmand Province, bitterly resents the politicians who sent them out there and aren’t willing to do the same. It takes a little longer for Budd’s heroism to give way to his extreme damage but by the end of the hour it’s clear that he’s dangerously volatile and more Travis Bickle than PC Plod. Separated from wife Vicky [Sophie Rundle], he’s in dire need of psychological help that he keeps refusing. As former army colleague Andy [Tom Brooke] says, “put PTSD on your application, who’s going to hire you?” Montague’s character couldn’t be in safer hands than Keeley Hawes’. Like Madden’s curiously numb, troubled Budd, Hawes is perfectly cast. With her clipped vowels and sound bite rhetoric about “paying tribute” and “making a real difference,” Montague is self-satisfied, unlikeable, and fluent in bullshit, all of which makes her utterly plausible as a senior minister. Throughout the hour, Mercurio and director Thomas Vincent grasp the viewer like a stressball in the palm of a hand. Squeeze, release, repeat. The train-set opening third wrings tension from unlikely sources—a toilet door sign switches from ‘engaged’ to ‘vacant’, phone signal dots disappear and ping back as if fired from a bow… It’s all expertly designed to grip; you can picture the exaggerated fingernail-biting reactions of the Gogglebox cast edited between each beat. We’ve not long to relax until the second instalment, which airs tomorrow before returning to a weekly Sunday night slot. Will Budd conquer his demons and make a proper go of civvy street? Will the terror cell whose attack he thwarted regroup? Will he take a bullet for a politician he despises? Would you? Bodyguard continues tomorrow, Monday the 27thof August at 9pm on BBC One.