BBC viewers have been left scratching their heads after a puzzling scene in the new drama series, Nightsleeper.

The new thriller, which aired for the first time on Sunday night (15 September), stars Peaky Blinders actor Joe Cole as Joe Roag, an off-duty police officer who finds himself on board a Glasgow to London sleeper train, which has been hijacked via a cyber attack.

As the episode unfolds, it transpires that the train is being controlled remotely and is being used as a missile. It leaves Joe and cyber security chief Abby Aysgarth (played by Alexandra Roach) as the only people who can stop it.

Viewers have been left questioning how realistic the plot is – especially a moment when Joe and Abby start singing the lyrics to Kate Nash’s “Foundations” to each other as the crisis escalates into a hostage situation.

One viewer wrote on social media: “Who among us can honestly say they’ve never had a jokey singalong to a Kate Nash song when caught up in a deadly terrorist attack?”

Another added: “Are they really singing Kate Nash when the train is in impending doom? I had high hopes for this.”

“#Nightsleeper is so absurd I am starting to wonder whether it’s intentional. So many plot holes it’s laughable. Giving episode 2 a go on iPlayer to see if it clarifies things,” said another viewer.

One viewer was more diplomatic as they concluded the series was “very watchable” but the dialogue was “toe-curlingly bad” including the “Kate Nash thing”.

“I’m sorry did two characters in a 2024 drama just flirtatiously quote Kate Nash lyrics at each other?” another chimed.

Another said the Kate Nash moment gets the “2024 mega-cringe award”.

In the show, criminals manage to install a physical device in the train’s control room to carry out the hack.

Joe and Abby have to work together to stop an impending train wreck, with Joe on the train trying to disable the hacking device while on the phone to Abby, whose team at the National Cyber Security Centre are frantically trying to work out who is behind the “hack-jack”.

As the series unfolds, the pair try to communicate via an unreliable satellite phone to save the lives of those on board.

In a two-star review of the series, The Guardian’s Lucy Mangan called the thriller “fantastically dreadful” with a “woeful script”.

“As the minutes and hours unfold, matters become increasingly ridiculous,” writes Mangan. “In addition, the words the poor actors are required to say become increasingly abysmal.”

Nightsleeper is streaming on BBC iPlayer now.