Ludwig
9pm, BBC One
An amusing comedy drama from Mark Brotherhood (Mount Pleasant, Benidorm) about a reclusive and socially inept puzzle-setter, John “Ludwig” Taylor (David Mitchell, doing his familiar young fogey thing). John is called on to impersonate his identical twin brother, a detective named James, after he goes missing. When James’s wife, Lucy (Anna Maxwell Martin), asks John to pick up some documents from James’s station, the inevitable happens: John finds himself investigating a murder. Phil Harrison
999: On the Front Line
8pm, Channel 4
The West Midlands ambulance service continues to battle an impossible level of demand, including a man who has stopped breathing outside a nightclub and a patient having a sickle-cell crisis. Tending to them requires a superhuman effort from the paramedics. Jack Seale
The Chelsea Detective
8pm, U&Drama
More drama from the darker side of one of London’s swankiest districts. In the first part of a double-episode story, a murdered security guard may have been the victim of a drug deal gone wrong. But then the detectives Max and Priya learn that he wasn’t as innocent as he seemed. Hollie Richardson
Parole
9pm, BBC Two
An intense insight into the route by which violent prisoners are allowed back into the community. First, we meet Martin, who murdered a friend with a table leg, and the Parole Board who will decide his fate. Their process, says one, involves the question: “Would I be concerned if this person moved in next to my mother?” PH
Grand Designs
9pm, Channel 4
Turning a coastguard’s station on an exposed Yorkshire headland into a comfortable home with a short deadline and a tight budget – what could possibly go wrong? Kevin McCloud’s property show returns with a fraught project in which Zahid and Ferzana appear to have bitten off more than they can chew. PH
Searching for Satoshi: The Mysterious Disappearance of the Bitcoin Creator
9.15pm, U&W
Who is Satoshi Nakamoto? Is he even one person? The title of this documentary is intriguing, but also a red herring – the show functions as a handy, simplified explanation of cryptocurrency, how it works and why it might expand in importance. As for Nakamoto, the mystery largely remains intact. PH
Live sport
English League Cup football: Liverpool v West Ham 7pm, Sky Sports Main Event. A third-round match at Anfield.