Crime procedurals are back, and David Mitchell’s new one is the best

LUDWIG ★★★★

Seven, Wednesday 5, 8.30pm, and 7Plus

John Taylor (David Mitchell), the timid but tenacious puzzle-maker at the centre of this wholly enjoyable detective tale, has a theory about coincidences – once you get to three, they’re no longer coincidences. If you apply that to the recent surge in mysteries in which the investigator is an idiosyncratic outsider, it’s not hard to find three welcome new shows where the protagonist clears cases while pursuing a secret mission: Ten’s Matlock, Disney+’s High Potential and now Seven’s Ludwig.

David Mitchell is an accidental detective in Ludwig.

The case-of-the-week procedural is back, complete with cold (corpse) opens and all the suspects being assembled. The twist is that the detectives in each show have a motivating force that keeps them pushing forward, a season-long search that endures after their latest assignment is successfully closed. Ludwig, I think, has the cleverest. A case of impersonation that makes for awkward tension, heartfelt failing and blithe humour. John Taylor is a fake.

A cheerful recluse, John constructs puzzles for a living, operating under the professional moniker of Ludwig. His life is so neatly self-contained that when his sister-in-law Lucy (Anna Maxwell Martin) summons him for a visit one night, she can correctly guess what he was planning for dinner (Sundays are pasta). Lucy had married James Taylor, John’s twin brother and the extrovert to his introvert. But after several months of moodiness, the Detective Chief Inspector from the Cambridge police has suddenly disappeared.

Lucy, who has known the twins since they were six years old, and more importantly knows how to smoothly coerce John, persuades him to impersonate his brother so they can keep his absence a secret and John can bring home the work files she believes will reveal what was plaguing her husband. John, who thought leaving the house was a big ask, reluctantly agrees, but as soon as he heads for James’ desk, his team are called out for the stabbing death of a solicitor in his office.

However, John realises his puzzling skills are applicable to a murder investigation. He’s so good at unfolding them that senior brass start paying attention to him. One of the pleasures of Ludwig is watching a shy underdog experience public success; in ego terms, John is the anti-Sherlock. And once he finds the coded notebook James left behind, John has a purpose – crack his brother’s secret (polyalphabetic ciphers are very much his thing). James just has to keep going back into the office, and, well, attending crime scenes.

Mark Brotherhood’s show has great fun with David Mitchell’s anxious subterfuge. Standing him opposite the towering Chief Constable Ziegler (Ralph Ineson and his suitably gravelly voice) gives off workplace terror. It doesn’t help that John refers to a “how did they die test”, which James’ new partner, the perplexed but supportive Detective Inspector Russell Carter (Dipo Ola), correctly translates as a “post-mortem”. Making small-talk stresses John out, but his innate goodness drives him onwards. Although he’s a terrible driver.

Mitchell, who will forever be known for Peep Show, is expertly cast, but John’s carefully drawn parameters are nowhere near as effective without Martin’s Lucy corralling her brother-in-law, and then opening up not just his purpose but his heart. Even as John and Lucy, who runs her own side investigation, search for James, John is reminded of his feelings for Lucy, who looks at him anew. It’s a welcome thorn in an enjoyable series. Ludwig is a breath of fresh air amid commercial free-to-air’s surfeit of reality shows.

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