Jesus, you think, you almost pushed that poor bastard out of a moving train! Heart beating, you realise you need to calm down, take five, get a damn grip.
You walk into the now vacated toilet and straight into a woman you didn't know was in there. "Sorry," you stammer right before you notice she's wearing a bulky homemade bomb belt and holding a trigger switch...
This, then, is how the incredibly tense, bloody brilliant new BBC thriller Bodyguard opens. Yes, opens.
The pace of telly has slowed so dramatically these days, labouring under the weight of its cinematic ambitions, that a suspense filled, edge-of-your-seat sequence like this could easily be a season finale. A satisfying pay-off for hours of your time.
Not so here. Instead, Bodyguard kicks off with all the momentum of a speeding train and all the urgency of a terror alert. In a lot of ways it's like the cold open of the Bond films. A big action set piece designed to sucker you in.
Only instead of Union Jack parachutes or parkour-worthy construction sites Bodyguard thrills you with the intense pressure of the situation, presenting what is essentially a supremely intense conversation but editing it with all the expert finesse of a big budget action scene.
Twenty minutes later it's all over, the series begins proper and Bodyguard gives you a chance to cool down. Only it doesn't because that terror situation is only the first big, heart pumping sequence of the first episode. Yes, there's more. And then the pace really begins to pick up in episode two...
All six episodes of Bodyguard are on Netflix now and I suspect it will be the series you binge through the quickest this year. Watching it after Netflix's much hyped, big budget bore Maniac - where nothing happened ever - is like a shot of adrenaline. A reminder of how engaging and engrossing the medium of telly can be.
So what's it about then? Well, the clue's right there in the name but a little more detail wouldn't hurt. An army vet now working as specialist protection officer for the London Police is assigned to protect an ambitious, divisive, hate-mongering conservative politician.
Together they're a big value terrorist target; her for her policies, him for the business on the train. This means action is never far away. One minute Sergeant David Budd is sizing up an empty street and talking into his sleeve mic, and before that minute ends he's shielding Home Secretary Julia Montague from meeting an early grave.
There's a lot of action and if I gave a rundown of the events from just the first two episodes it would sound hugely improbable. But Bodyguard never feels anything other than grounded and realistic. Despite mentioning the action a lot here, Bodyguard isn't an action show. Not really. These scenes are intense and suspense-filled as opposed to being all-guns-blazing, explosion-filled mayhem.
Even in the show's quieter moments the tension never lets up. Aside from the constant terror threat there's also side plots revolving around PTSD, a family separation, a possible political coup, an aggrieved ex-aide, an ill-advised office romance and conflict between the heads of Britain's various intelligence and security forces.
Even simple conversations are cut tight and close-up making something as innocuous as the morning drive to the office a heightened, uneasy viewing experience.
Supremely popular in its homeland of merry ol' Blighty, Bodyguard has been the most watched show of this year, pulling an audience of over 10 million. That many Brits can't be wrong. Unless, of course, we're talking about Brexit...
Okay, bad example. Don't let that put you off. Bodyguard is television at its best.