Whilst Stacey is thrilled to be living back home Gavin tries to come to terms with the culture shock of working with his new Welsh colleagues. Nessa, now living with Dave, throws a christening party for baby Neil, attended by the Shipmans and Smithy and Rudi and their narcoleptic mother Cath. Bryn's lusty singing at the church inspires Pam in her desire to be on "Britain's Got Talent" but Smithy, having paid for the christening, is annoyed to learn that it is doubling as Nessa and Dave's engagement party. Gavin and Stacey, however, are inspired by the occasion to consider starting their own family.

Stacey interviews for a new job while ensuring that Gavin sticks to his recent promise, and Dave is not a happy bunny when Nessa tells him she is taking baby Neil to Essex to see his dad.

Pam and Mick are having second thoughts about the conservatory; Bryn is in his element as he awaits the arrival of his houseguests: all the Essex boys down for a big night out in Cardiff.

Pete and Dawn are ready for a fresh start and decide to renew their vows, although Pete's ring threatens to ruin the big day. Meanwhile, Gavin and Stacey receive some awful news.

Pam and Mick unexpectedly arrive in Barry, and everyone, including Smithy and Doris, decides to spend the sunny day on the beach. But there are two questions on everyone's mind: will Dave be there? And, is Gavin really OK?

The wedding day of Nessa and Dave Coaches has dawned, and everyone is looking forward to the big event--except for Smithy, who faces a dilemma.