Xinzhou aired on BBC Radio 4 on January 30th and starred:
- Benedict Cumberbatch as Martin
- Roger Allam as Douglas
- Stephanie Cole as Carolyn
- John Finnemore as Arthur
- Lobo Chan as Xinzhou ATC
There is no pre-credits sequence for this episode. The episode opens Arthur humming to himself as he finishes making a snowman. There's 20 minutes left until the airport closes and Martin's busy chasing his hat around the airfield. Martin comes back in and then gets told to go back outside to do the walk round. Douglas talks to ATC and Martin comes in covered in snow. The APU is dead and Martin is concerned about the snow.
Outside GERTI, Martin and Douglas are discussing how the snow is, Martin believes that it's too slushy, but Douglas proves him wrong by pelting him with a snowball and pointing out Arthur's snowman. As they're about to leave, they are called back because of Arthur's snowman and are not allowed to leave again until they've collected it, missing their dusk take off slot. Since the APU is down as well, they're forced to spend the night onboard GERTI, much to Arthur's surprise and enjoyment.
The crew settles in for the next 8 hours onboard GERTI. The food situation is a little bleak as Arthur made a mistake on the flight and instead of ordering lamb and poussin, he ordered lamb and chicken flavoured baby food. After eating their meals, they relax and then start to play games to try and relieve the boredom and fall asleep. Sleep doesn't last long between bouts of the warning alarm going off that they have to fix every 20 minutes.
Carolyn reveals that Hercules might be moving to Zurich or taking retirement. It's a decision that they have to make. It has Martin interested, who also reveals his relationship with Theresa has gotten better. Carolyn suggests that he should go for a job with Swiss Air, as he'd be closer to Theresa. Arthur has been gone too long, so they find him outside building a second snowman. They move it under the tail to keep the APU inlet clear It's topped off with Martin's hat.