"Praxeus"

Pete McTighe's "Kerblam!" was a very enjoyable story and, like Ed Hime, I was keen to see him come back. Like Hime's "Orphan 55", "Praxeus" is s standalone adventure with a strong environmental streak. Unlike "Orphan 55", "Praxeus", is an astonishing example of how fantastic such a story can be. The only villain in the story is short-sightedness – the alien humanoids lack of care in experimenting on Earth and, of course, the main subject of the episodes – microplastic. Like Robert Holmes looking at how many plastic gadgets and products surround the average person and creating the Autons, McTighe and Chibnall look at the disturbing accumulation of the detritus left from those same plastics breaking down, and created one of the most terrifying threats the programme has ever had – the plastic-mutating Praxeus virus. The plotting and pacing are frequently relentless, but the varied locations and adrenaline-charged scenes illustrate that this is a global problem and an urgent one, which is why the Doctor enters the scene running and barely lets up.

The writers have created what is the best use of the fam and their dynamic, yet. For most of the episode, the fam is split into three groups and all three of the fam-ily have their 'Doctor-y' moments – Ryan is the first to appear in the story and that scene has some of the same beats as the Doctor's first appearance in "Rose". Best of all is that, for the first time since "Demons of the Punjab", Yas truly shines – her disappointment at not having discovered an alien planet is hilarious, as is her correction of Graham's use of the scanner. The Doctor is given, perhaps, the most Doctor-y challenge to overcome – saving her favourite species from their own short-sightedness and Jodie Whittaker is on fire. In such a maelstrom, characterisation can suffer, but here, supporting characters are given enough nuances to register, with slightly needy vlogger Gabriela and the Doctor's science crush Suki, who, of course ends up disappointing her. The main support comes from Warren Brown and Matthew McNulty as Jake and Adam, a mismatched, yet wholly believable married couple, which gives the episode its few respites from the breakneck pace.

Jamie Magnus Stone returns to realise this frenetic tale and he uses the vivid locations to paint an epic globe-trotting experience. The most effective sequences are, of course, the manifestation of the Praxeus virus. The flocks of birds are reminiscent of Hitchcock, and all the better for it. The symptoms of the virus are utterly horrifying and very well shot and edited. They are more terrifying than the corpse mutilation in "The Woman Who Fell to Earth", yet, unlike Tim Shaw's trophy hunting, not crossing the line in appropriateness – an important distinction that Chibnall has learnt.

"Praxeus" starts and ends with a David Attenborough-style narration by the Doctor, but the wearing of its environmentalist heart on its sleeve feels far less preachy than in "Orphan 55" and only makes this vibrant story all the more appealing.

NEXT: Can You Hear Me?