Anna Maxwell Martin is probably best known for her role as DCS Patricia Carmichael in the hit BBC crime drama Line of Duty, as well as her role as Julia in the popular BBC comedy show Motherland. More than recently, she starred alongside Gavin & Stacey star James Corden in the play The Constituent at the Old Vic Theatre.

John's sister-in-law Lucy, played by Anna Maxwell Martin in an enviable wardrobe of autumnal jumpers, enlists his help. This is where things start to get a bit daft, but bear with, because it works in the mood of the show.

Puzzle setter John ‘Ludwig’ Taylor’s life is upended when his identical twin, DCI James Taylor, disappears in the new series coming to BBC iPlayer and BBC One

BBC One's new comedy-drama series sees a reclusive puzzle setter forced to come out of his shell when his identical twin brother James disappears

David Mitchell has spoken about his fears around working with Anna Maxwell Martin on their new BBC show Ludwig.

Puzzle setter John Ludwig Taylor’s (David Mitchell) life of solitude is upended when his identical twin, DCI James Taylor, disappears. Drafted in by his sister-in-law Lucy (Anna Maxwell Martin), John reluctantly assumes his brother's identity as a detective in the Cambridge Police Authority in order to find clues to his brother’s whereabouts.

Ludwig BBC One, 9pm On-the-spectrum detectives have comprehensively replaced the traditional hard-drinking, music-loving mavericks of classic TV crime drama. From Sherlock and The Bridge to Professor T,

Yet that’s precisely what’s required of John in Ludwig, a new BBC comedy-mystery series starring David Mitchell. Working well within his comfort zone, he plays John like a not-so distant relative of Mark Corrigan,

Is Ludwig (BBC One, 9pm, Wednesdays) just another TV murder mystery? I’ll admit, the opening scene had me worried.