St. Petersburg aired on BBC Radio 4 on 5th August 2011 and starred:
- Benedict Cumberbatch as Martin
- Roger Allam as Douglas
- Stephanie Cole as Carolyn
- John Finnemore as Arthur
- Timothy West as Gordon Shappey
- Paul Shearer as Tommo
The episode has a pre-credits sequence. In this instance, Carolyn is giving a cabin address to a bunch of Russian Yacht Brokers who are coming back from Saint Tropez. She also states that they'd be insulted if they were offered a tip. Douglas interjects on the intercom by stating that they are the pilots and would people like to slide the insults under the flight deck door.
The episode opens with Douglas doing a rather fast walkaround in minus 19 weather in St. Petersburg. He asks Carolyn for vodka, as Arthur seems to have frozen himself to the hold door. Carolyn asks if she can use water, but Douglas explains that vodka is better as it has a lower freezing point and won't injure him. Douglas unsticks him from the hold door but then has to use it again when Arthur puts the keys in his mouth to put his gloves on.
Inside the flight deck, they start the take off procedures. Arthur is drunk. During the flight home, they begin of game of Rhyming Journeys, Their game is interrupted by a bird strike which causes an engine fire. They are forced to return to St. Petersburg for immediate repairs. They get there and discuss their options as a new engine will set them back a quarter of a million, which they don't have. One of their options is to sell GERTI for scrap and use the money to get home. The only other option is to sell it to Gordon Shappey, Carolyn's ex-husband who's been after the plane for years. Faced with no real opportunity, that's what they decide to do.
Martin and Douglas are sat in the staff canteen, eating their meals, when they meet Gordon and his mechanic Tommo. They go out to the hangar so Gordon can go and check the plane out and come back in a few hours with an offer. Arthur hasn't found any toblerones for a present. Gordon comes back and offers Carolyn £500 for GERTI. He states that he intends to break her up for parts and keep the tail fin, which he'll put NYBJAMS on it (Not Your Bloody Jet Any More Sweetheart) and then leaves after Carolyn says £100,000 and that's the final offer.
After they leave for their hotel, Douglas gets an idea and returns to the airport. He checks GERTI and finds out that Gordon had a new engine bolted on. Douglas realises that Gordon intended to steal GERTI, based on the facts that he booked the office in MJN's name, he's qualified to fly her, he still has door key and why his engineers took so long to look at it. This is when they hatch a plan.
Gordon enters GERTI and suddenly finds himself stuck to the controls. Douglas and Carolyn emerge from their hiding places. They reveal that they removed the control column, put it in the snow for 20 minutes and put it back into place. Gordon tries to get them to let him go and they force him to hand over the engine in exchange for the bottle of Gordon's Gin that Arthur had bought for him. Carolyn chases him off GERTI. Outside, they find Arthur asleep. They pick him up and take him onboard and realises that his notion that Douglas would do something clever and fix it was right afterall.