Doctor Who review, Kerblam! – Jodie Whittaker's seventh outing is perfectly judged

With Christmas suddenly looming and thoughts turning to online shopping, Jodie Whittaker's seventh outing as the Doctor is perfectly judged. The setting is a deep-space version of an Amazon warehouse – or at least an Amazon warehouse if it was the backdrop for the wackiest ever episode of Westworld.

Despite living in a blue box that traverses time and space, the Doctor is somehow at home when her internet order of a Fez hat is delivered (talk about untrammelled fantasy).

But along with the natty headgear is a note pleading for help. Obviously she has no choice but to immediately divert course, along with her regular crew of Yaz (Mandip Gill), Ryan (Tosin Cole) and Graham (Bradley Walsh).

Their destination is the moon-size shipping centre of the all powerful Kerblam corporation – a dystopian virtual retailer whose packages are conveyed by cheery/creepy robots resembling cyberpunk Postman Pats.

Kerblam would run perfectly well as a machine-only enterprise. As a concession to pesky humans, however, 10 per cent of the workforce is “organic”. What could go wrong? Lots, it turns out. Several “organics” have vanished recently and now friendly warehouse worker Dan (comedian Lee Mack) has joined the missing.

This is, at one level, a serious instalment with a sobering message about the replacement of humans by machines. However, Kerblam also brims with irascible wit (the Postman Pat-bots are unnerving but there's something hilarious to their creepiness). And with Doctor and crew soon go pegging around the infinite warehouse, having passed themselves off as new recruits, the hour zips by.

It all adds up to an important course correction after last week's despair-filled rumination on the partition of India – an hour of sci-fi sociopolitics that sent my eight year old to bed confused and a bit depressed (not what you want on a school night).

The stark humour carries through to secret villain Charlie (Leo Flanagan) and his plan for wiping out tens of thousands of Kerblam customers. His goal is to fuel a backlash against machines and create more jobs for humans (genius, they should make him Brexit Secretary). He's invented a deadly strain of bubble rap, which explodes with a single pop – the first law of human behaviour being nobody can resist bubble rap.

The big reveal is that the cry for help received by the Doctor is from the Kerblam hive mind, not from any of the flesh and blood employees on the moon. But the other arguable twist is the creative casting. Mack displays surprising acting chops and show-runner Chris Chibnall's old Broadchurch mucker Julie Hesmondhalgh pops up as Kerblam's very confused head of human resources (Matthew Gravelle, likewise from Broadchurch, provides Kerblam's scary gameshow-host voice).

With the day saved – though Charlie's work crush Kira (Claudia Jessie) comes to a sticky end – the upbeat ending also provides a nice contrast to the mopey tone of the previous episode. This, in other words, is Doctor Who at its finely teased best. There's a grown-up point – do we really all want to be replaced by machines? – but also lashings of quippy banter and funny/scary robots. Just what the Doctor ordered.