In this series, we have been given unprecedented access to two of the biggest teams in Formula 1 - Mercedes and Williams. It’s a few days after the final race of the 2023 season, and the teams are returning home to their UK factories after an epic year. It’s time to enjoy the year’s hard-fought success with the workforce of hundreds back at base. And we are there with them - our F1 experts Holly Samos and Sarah Holt added to the guest list.

After a dramatic season finale in Abu Dhabi, the sport’s seven-time World Champion, Lewis Hamilton, and team principal, Toto Wolff, are leading the celebrations at the Mercedes team’s twin facilities at Brackley and Brixworth. But there is a familiar face missing.

At Williams’ home in Oxfordshire, the historic team’s star drivers, Alex Albon and Logan Sargeant, have also come home. But for Sargeant, who made his F1 debut for Williams in 2023, the American’s future remains uncertain. Will he keep his place as one of just 20 drivers on the F1 grid? That’s a decision for James Vowles, who has had to make a few big calls in his first season as team principal - and his first since leaving Mercedes.

The homecoming - as happy as it is - is only a brief pause. Formula 1 is a shark. It’s always moving forward. Mercedes and Williams are not standing still. Because the winter is when the real work begins. For the teams. For the drivers. For the men and women designing, manufacturing and building the cars that will race in the 2024 season.

It’s impossible to know what lies ahead but before he leaves to spend the holiday season in America, Lewis Hamilton has one more visit to make. He’s going to a top-secret part of the Mercedes’ factory.

F1: Back at Base is an IMG Production for the BBC