Katherine Kelly's In Flight deftly avoids one thriller misstep – only to fall right into another

It's a format which works, hence why we've seen it so many times before - just in the past couple of years we've seen it with Apple TV+'s Hijack, ITV's Red Eye, and the BBC's Nightsleeper.

It's no coincidence that two of those take place on a plane. A thriller in mid-air is, naturally, a compelling premise, and there's more reason than with any other mode of transport as to why the characters can't simply get off.

However, it has to be said that were In Flight to take this route, I personally would have let out a rather mighty sigh.

By this point, we really have seen it all before with that premise, and in a time when TV (in certain quarters) feels as though it's becoming less risk averse, a thriller attempting to ape the success of other series, none of which were all that innovative to begin with, would feel more like a chore to get through than an enjoyable, engaging piece of television.

On that front, one big tick goes in In Flight's favour. Very little of it (at least across the first half of the season) takes place on board a plane, with the premise instead centred around the predicament Jo, a flight attendant and single mother, finds herself in.

Played superbly by Katherine Kelly, we meet Jo as she is grappling with the knowledge that her son, Sonny, has been imprisoned in Bulgaria.

Sonny was on a night out when a murder occurred, and he has taken the rap for it. He insists that he didn't do it and that he has been set up, and Jo is inclined to believe him.

Jo's life is, therefore, already in turmoil when she is approached by Cormac, a man who at first appears like he is coming on to her at a bar, but later turns out to have a much more sinister motive.

Cormac is part of a gang which has access to Sonny in jail. He tells Jo that if she goes to the police or tells anyone about what's going on, Sonny will be put in grave danger.

Instead, if she complies, Sonny will get protection in prison. What Jo has to do to ensure this is to, while going about her usual business at her job, transport large quantities of heroin into the country from the various destinations to which she travels. It is reasoned that because she is a flight attendant she will easily be able to fade into obscurity and slip past customs.

All of this sounds relatively promising, and there are things to like about In Flight. The set-up is strong and brisk and, as already mentioned, Kelly gives a phenomenal performance, really selling Jo's resilience, but also the unbearable nature of the the stress and trauma that she is going through in some heartbreaking scenes.

Unfortunately, this is also part of the problem, as In Flight falls into a trap that has also foiled many other thrillers in the past - it is just far too bleak for its own good.

While we see very brief glimpses of what Jo's life might have been like before Sonny was imprisoned, we only actually meet her after the fact, when she is already in the midst of a crisis.

From there on out it is just a barrage of terrible news for her, as she finds herself in an ever-worsening situation, all while fearing that her son could spend the rest of his life in prison - or worse.

Some shows can pull this off - things can go from bad to worse for a character without a series feeling tonally skewed too far in one direction. A prime example is The Stolen Girl, which arrived earlier this year, dealt with some really heavy subject matter, but never felt grim. Instead, it felt exciting, propulsive and kept you guessing throughout.

In Flight doesn't achieve this, and instead ends up more miserable than nerve-wracking. Perhaps the biggest reason for this is that it just isn't propulsive or engaging enough to make the bleakness feel worthwhile.

There are moments of tension for sure, and some well-done sequences where Jo seems like she is about to be undone, but there's far too much meandering. Just as Jo doesn't know where all this is heading, and how long she could be trapped in this unwanted criminal lifestyle, neither do we.

Thrillers can take themselves seriously, of course they can. But delving too much into the emotional reality of a situation can be to a show's detriment, particularly when its primary objective is to entertain us. Were this a drama aiming to stun us into silence and make us go through the wringer emotionally, it would be a different story.

But the premise here is too outlandish, and the set-up too evidently in the thriller genre, that we do have certain expectations of a fun watch. Beyond the very occasional moment of levity, each of which really does shine through in its rarity, this is a sombre affair.

Other shows also get around this by involving additional characters who are less emotionally tied to the central protagonist's circumstances, but In Flight is incredibly single-minded.

Beyond Jo, the only other properly central characters across the first three episodes are Sonny, who is having an extremely bad time, Cormac, who we only see through Jo's lens and who is hardly a barrel of laughs, and Dom, her ex and a customs officer played by Ashley Thomas.

Dom feels like the character where the most levity could naturally live, as he's just enough outside of Jo's predicament to add some light to counter the shade. Unfortunately, that's not the case - he's just as serious and grave as everyone else here.

All this also isn't helped by the fact that the series is not just thematically dark but also literally, with an extraordinary amount of its runtime taking place at night or in dimly lit rooms.

The monotonous look of the show makes everything just that bit more dreary, potentially helping to up the tension somewhat, but also making it all more oppressive for the viewer.

Perhaps my criticism is also borne out of the era of TV in which this is being released. One can imagine that this series would have felt more at home in the 2010s, when gritty thrillers were the name of the game.

But in the present day, when many of us are looking for a bit more escapist fun from our TV, and especially from our thrillers, it sticks out like a sore thumb.

Kelly should be praised for the outstanding work she does here, and there are no doubt elements to enjoy.

But it does feel as though In Flight has fallen into the trap of thinking that dark, authentic and tense has to mean miserable - when that couldn't be further from the truth.

In Flight premieres on Channel 4 on Tuesday 12th August 2025.

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