he Flight Attendant will do nothing to reassure those of us who have long held the theory that there is no demographic more mad than those who work as air stewards and stewardesses. Not only do they look at all the jobs they could do on the ground – the safe, safe solid ground – and say “No, I’d prefer to be travelling through the clouds in a pressurised metal tube held up by forces so mysterious they amount virtually to magic”, they also embrace the duty of hospitality, or “being endlessly nice to people no matter how awfully they behave”. In HBO’s new comedy-drama (shown here on Sky One), febrile but functioning alcoholic Cassie (Kaley Cuoco) has embraced her hospitality duty fully. Every time a passenger gets a drink, she gets one too, and in the opening episode she flirts with handsome gazillionaire passenger Alex Sokolov (Michiel Huisman) on a flight to Bangkok and ends up spending a fabulous, inebriated night with him. Alas, the fun stops abruptly for our gal when she wakes up to find him bloodied and dead beside her. His throat has been cut and she cannot remember anything of the night before. She cleans up the crime scene and hotfoots it out of there, unaware that her colleagues saw her head off on an obvious date the previous evening, and only discovers later that her ID is missing. On returning home she is questioned with the rest of the crew by FBI agents who have been informed of Sokolov’s murder during his – ahem – layover, and suspect espionage shenanigans. As pieces of the night before start to flash into Cassie’s mind – including the revelation that there was at some point a third person with them – she begins to wonder who the murderer might be. It’s an hour that, pardon the pun, flies by. The premise is fun, the execution is slick and the action is fast and relentless (it only really pauses to let Cassie top up her blood-alcohol level or call her straight-arrow brother to assure him that she’s sober and will be home on time). It’s full of style and brio, from split-screen scenes when she’s talking to her brother or to her lawyer friend Annie (Zosia Mamet, doing her wonderful bonkersly-detached thing) to the hallucinations involving Alex’s risen corpse. The script is a thing of wonder: propulsive and credible despite its fundamentally incredible premise. It even nails the hardest thing of all: convincing workplace banter. Cassie’s fellow flight attendants include Rosie Perez as Megan Briscoe, her closest friend there, torn between lying to the FBI and betraying her friend, and reminding us at every turn what a fleet and funny actor she is. Above all, though, there’s Kaley Cuoco. And this, after 12 years as Penny on The Big Bang Theory, is unassailably her show. Her comic timing and hitherto unsuspected dramatic chops (by viewers at least – the casting director deserves an award to go alongside all those for which Cuoco has already been nominated as a result of her role here) ground and charge every scene. She gives charm, wit and true confidence to a character who would otherwise be a hot mess we would neither care about nor believe in. It’s joyfully astonishing to see her spread her wings – and fly.