Light relief in the dreary first full working week of the year came from the return of Cabin Pressure to Radio 4. One of the station's few contemporary sitcom successes (more on that subject another week), it has lured Benedict Cumberbatch and Roger Allam back for a fourth run at playing odd-couple pilots Martin and Douglas. The pair man MJN Air: a tinpot, one-plane budget airline owned by middle-aged divorcee Carolyn, played by Stephanie Cole. It's an impressive cast - Allam does a great line in supercilious grumps and he is in his element as the snarky first officer to Cumberbatch's prissy, uptight captain. But perhaps the real star of the show is its writer John Finnemore, who also plays Carolyn's doofus air-steward son, Arthur.

"The code red is there to stop me being too helpful, and I can't stop being too helpful by being more helpful," he bumbled at his mum, in a script packed tight with superb lines. The crew had assembled for Birling Day, the annual jolly enjoyed by their stupidly rich (and often drunk) regular customer, who charters a flight each year to take him to see the Six Nations rugby final. Except this year, the match was taking place at Twickenham, a short drive from Birling's own house. No matter.

After a row with his wife and in a fit of pique, Birling ordered a trip to watch the match in Timbuktu. Miles of daft behaviour followed, the highlight being Allam's smug laugh - "Madame is a humourist?" - as Douglas bartered with Carolyn over a bottle of whisky.

John Finnemore: Timbuktu episode blog

John Finnemore explains the thinking behind the 'Timbuktu' Birling Day linked episode of Cabin Pressure.

Hurray! Here's the fourth series of John Finnemore's splendid comedy made magical by the brilliance of its cast. Stephanie Cole plays Carolyn Knapp-Shappey, formidable owner of a one-plane airline. Benedict Cumberbatch is the sole Captain, Roger Allam as First Officer provides a one-man masterclass in timing and Finnemore himself plays the owner's cheerfully hapless son. There's enough here to banish the New Year blues, even if your electricity bill just arrived.