Anthony Jeselnik starts the first of his two shows at the Edinburgh Fringe with the greatest opening joke of all time. 

Not my words, you understand, but his; this American comic’s staggering arrogance being part of his shtick as the world’s biggest, most insensitive asshole.

Over the hour, this callous bastard kills and rapes, bullies a disabled girl, mocks an Alzheimer’s sufferer and advocates for murder-suicide. There are aren’t enough trigger warnings to cover his depravities.

But while the punchlines are brutally offensive, what separates him from the worst excesses of gross-out frat boy humour is the precision of his writing and the elegance of his performance. 

The jokes are efficiently short yet still contain plenty of misdirection. Even though you know each one must end in a terrible place, he sneaks around to still take you by surprise.

And in his best routines – such as the one about dropping a baby or the 15-minute closing routine about taking a friend to an abortion clinic, with him thinking the most inappropriate thoughts at every turn – the picture is built up layer-by-layer, each line adding a new coat of horror on to the already unpalatable situation.

The craftsmanship that goes into his writing is matched by a classy delivery, languidly unhurried with the ice-cool Jeselnik in control of every slightly-too-long pause, leading to a delicious anticipation of what atrocities are to come, keeping the audience teetering at the top of a bad-taste rollercoaster before releasing the brakes.

He has the calm swagger of someone with nothing to prove, slowly prowling the stage and reprimanding anyone who isn’t in thrall to his depravities. ‘If you’re not laughing at that, the problem is your imagination,’ he comments after evoking one particularly vivid – and yes, objectionable, image. 

Jeselnik’s sneering vanity is, counterintuitively, part of his appeal. It’s such an obvious stage construct that it takes the sting out of his most appalling punchlines, by underlining that it’s ‘just jokes’.

He never deviates from the low, which doesn’t give the show any tonal variation, but if you’ve a stomach for sick comedy,  Jeselnik will deliver with a rare grace.