It has been ten years since we last went to Billericay to spend Christmas with the Shipmans and the Wests. This year we're off to Wales for the festivities, where Bryn is cooking dinner for over 13 people. Understandably he's tense. Pam would secretly prefer to spend Christmas in Essex, as she finds Gwen's house a bit lacking. But the deal has always been that they alternate every year, and this time it's the turn of the Wests to host Christmas with everyone under one small roof.

For Gavin and Stacey, parenthood continues to present them with several challenges, their 'baby' now being ten. Smithy, too, continues to commit to his fatherly role, making the journey to Barry at weekends and every second Wednesday to see 12-year-old Neil the Baby. Nessa, on the other hand, adopts her own brand of Nessa-style mothering, whilst Pam, Mick and Gwen have become the epitome of doting grandparents.

On Christmas Eve, Dawn makes a shocking discovery about Pete that jeopardizes their marriage (again), and a visit to the pub that night is an eye-opener in more ways than one.

Nessa and Dave's wedding is fast approaching, and the preparations are in full swing. Stacey breaks some life-changing news to Gavin, while Bryn and Jason finally put their big secret to bed.

Smithy takes care of Neil the baby, and wishes Nessa all the best as she makes her way to the church to marry Dave.

It is Bank Holiday Monday, and the Essex contingent arrives for a sunny day out at the beach; even Doris gets her sun dress on.

Gavin's heart-to-heart with his dad gives him something more to think about, and a dark cloud looms on the horizon when Dave arrives to find Nessa and Smithy enjoying all the fun of the fair.

Gavin is uncomfortable with Gwen and Bryn knowing the ins and outs of his and Stacey's sex life, and Smithy goes beyond the call of friendship by making a staggering suggestion. Pete and Dawn prepare to renewtheir wedding vows and everyone heads to Billericay to help them celebrate. How will Dave react to the bombshell revelation about the curry night in Essex?

Pam and Mick are having second thoughts about the conservatory, whilst Bryn is in his element as he awaits the arrival of his houseguests - all the Essex boys are down for a big night out in Cardiff, and having a sleepover at his! Smithy gets in a state about seeing Nessa after their most recent embarrassing meeting and Stacey makes a worrying discovery. But is telling Gavin the right thing to do?

Stacey is trying for a new job whilst ensuring that Gavin sticks to his recent promise. Dave is not a happy bunny when Nessa tells him she's taking Neil the baby to Essex to see his dad. Meanwhile, over at the Shipmans' house, Dawn and Pete have joined Pam and Mick for a beer and curry night of huge proportions - at the Billericay house of fun.

Gavin starts his new job in Cardiff, and Stacey is thrilled to be at home again. Smithy comes to terms with life in Essex without his best mate, while Nessa is adjusting to life in Dave's caravan down in Sully.

The weekend brings with it a big reunion, as everyone meets up for the christening of Neil the baby. How will Smithy react to news from Nessa that it is a double celebration, and what will Gavin's answer be to Stacey's request?