Race Across The World | Series 4 Preview (BBC One)

Five teams of intrepid Brits battle it out in a breathtaking 15,000 kilometre race across eastern Asian through some of the world's most populous regions and some of its most unexplored.

The teams will race from northernmost Japan, crossing six seas and eight borders, skirting the path of volcanic ring of fire - the most geologically unstable region on the planet - to reach the finish line in Lombok, an idyllic Indonesian island paradise.

It's a journey that will see them race through multipole countries, including experiencing Japan's clash of ancient traditions with the ultra-modern, unexpected South Korea. They will come face to face with chaotic and colourful Vietnam and brave the unexplored Indonesian archipelago - the largest Muslim nation in the world.

Leaving behind their smartphones, internet and access and bank cards, they will be armed only with the cash equivalent of the airfare from Sapporo to Lombok.

The race begins in Sapporo, the capital city of Hokkaido, the most northerly of the four main islands of Japan. To reach the first checkpoint in Nara City, the teams face 1,600 kilometres through one of the most expensive countries where only a small percentage of the population speak English. With a myriad of routes to choose from, they must use all their skills, ingenuity and determination to make it off the island and to the checkpoint.

At just 20 years old, the youngest competitors of the race, trainee pilot Owen and football referee Alfie from St Albans have a shared love of travel and a drive to win. Best friends since Year 7, the determined pair fast-track to Tokyo, where they stumble upon the Naki Sumo festival - a curious competition where babies are judges for their ability to cry first .But will their unswerving competitiveness to win come at a cost?

Retired couple Stephen, 61, and Viv, 65, from Rutland, are embarking on a quest for one of last thrilling adventure before they 'dribble into old age'. Armed with wisdom and perspective, they believe their maturity will give them an edge over their younger competitors, but a slow start being that thinking into question.

For the first time there are two mother-and-daughter pairings in the race. Isabel, a trainee clinical scientist, is logical and likes to plan, whereas mum Eugenie, a teacher, is spontaneous and led by their heart. Isabel's strategic thinking leads to a surprising decision that yields unexpected results. But as they attempt to merge their two contrasting strengths, they hit multiple bumps in the road.

Sharon, 52, a cleaner from Kent, and her daughter Byrdie, 25, a snowboarding instructor, are determined to use their budgeting and people skills as a strategy to help cope with the challenges that come with Byrdie's dyslexia and get the edge on the other teams. Some chance interactions with Japanese locals prove that it can pay to be kind as they receive help along the way.

Well-travelled Betty, 25, and her younger brother James, 21, who prefers holidaying in Magaluf with the lads, have barely known each other as adults. The siblings from Yorkshire need to find a way of working together to get off the island of Hokkaido. But with such different approaches to travel and life, this doesn't come easily, and they hit a rocky start when a decision needs to be made.

As the teams close in on the checkpoint in Nara City, one of the most exciting races in the series' history ensues in the battle for pole position. The race will test the five teams both physically and emotionally, pushing them to their limits.

But with their feet on the ground, and their eyes wide open, the rewards will be great, and the memories will be everlasting. Only one team can emerge victorious as they all vie to be first and claim the cash prize of £20,000.

Race Across The World returns Wednesday 10th April at 9pm on BBC One and iPlayer.