Jones is hugging a cup of tea, waiting to be called for a scene where she will be dancing to Abba, and thinking about how close they are to the end, but how pleased they all are that it is on their terms.
“This is a full stop,” she says ruefully.
“I think we are very lucky to get to choose to end it, rather than to be told, ‘Sorry, we don’t want anymore.’ I think it’s lovely to be able to say a very healthy farewell to it.
Before we go, I ask James Corden, how he would like the show to be remembered.
He takes his time to really think about this and then talks at length about what he believes to be the show’s DNA, including “all the stuff that makes life good, which is friends, family and love”.
The conclusion to his thesis is: “I hope it’s remembered as a show that can make people feel good, that can bring comfort and a sense of warmth and history. That would be lovely if people spoke about it like that.”
Now he is waiting to see how the finale is received.
“If we can land the plane safely and just give it over to everybody else on Christmas Day, I don’t know, what a trip man, what an absolute trip it’s all been.”
Gavin & Stacey: The Making of the Finale, a 26-minute documentary, is available on the iPlayer now. The finale itself is broadcast at 21:00 GMT on Christmas Day on BBC One.