There's no doubt about the television event of the week – tonight's 50th anniversary special The Day of the Doctor – but since that is already swamped in hype, and unseen by previewers (who knows? Perhaps it's a turkey) let me draw your attention instead to Paula Milne's Le Carré-esque drama in BBC2's Cold War season, Legacy. Set during the industrial unrest of 1974 Britain, and shot with suitably drained and subfusc cinematography, it stars Charlie Cox as Charles Thoroughgood, a trainee MI6 agent who discovers that his late father had a sideline in installing listening devices for the KGB. Romola Garai (The Hour) plays a fellow MI6 agent, Andrew Scott (Sherlock) is a Russian and Simon Russell Beale excels as Thoroughgood's choleric, chain-smoking intelligence boss.
2. Doctor Who: The Day of the Doctor
What more can be said about the 50th anniversary episode? To recap what is known: Matt Smith and his predecessor David Tennant are joined by John Hurt as a third Doctor, as something terrible awakes in London's National Gallery in 2013, a murderous plot is afoot in Elizabethan England and an ancient battle reaches its devastating conclusion somewhere out in space.
3. Finding Babylon's Hanging Garden – Secret History
8pm Channel 4
One of the seven wonders of the ancient world, the Hanging Gardens of Babylon are the only one for which no archaeological evidence has ever been found. Stephanie Dalley, a code-breaker and expert in cuneiform writing – has decoded a long-overlooked text in the British Museum and now believes the gardens were built in another time and at a different location. The only problem is that it lies in war-torn northern Iraq...
4. Undercover: the Truth about Amazon – Panorama
Amazon has helped transform the way people shop – but how does the company treat the employees who retrieve orders? Panorama goes undercover to investigate.
5. Imagine – Hitler, the Tiger and Me
The children's writer Judith Kerr, author of the much-loved Mog books and The Tiger Who Came to Tea, has just turned 90, walking an hour each day and still enjoying a martini at lunchtime. More remarkable is her back-story, and Alan Yentob accompanies her to Berlin, and the family home she fled in 1933 aged nine with her Jewish intellectual father, and also hears about her marriage to Nigel Kneale.
6. CS Lewis: the Secret Lives and Loves
9pm & 2.30am BBC4
AN Wilson goes in search of the man behind Narnia – the children's author and world-famous Christian writer, who died on the same day as the assassination of JF Kennedy.
7. Kangaroo Dundee
Chris “Brolga” Barnes, an Australian who has dedicated his life to saving young orphaned kangaroos whose mothers were killed by motorists, and who was the subject of a charming Natural World film earlier this year, now gets an entire series.