When inexperienced traveller Sean realises that his best mate Dylan’s come to China to try and get back together with his ex-girlfriend, Lauren, he’s pretty upset. Sean had thought they were going on a lads’ holiday together – to reconnect after Dylan’s first year at uni. Things seem brighter when the pair hook up with two American girls, Ashley and May and hanger-on Greg. May’s mum is paying for her China trip so that May can reconnect with the Chinese side of her family, and have an authentic Chinese experience, and Ash is tagging along for an all-expenses paid trip. The five camp out together at the Great Wall and Dylan and Sean make it up to one another. But by the end of a crazy night at a music festival on the Wall, Sean finds himself separated from the group and lost in China.

May has to go to a family wedding in Hangzhou and is reluctantly persuaded to take Ashley, Greg and Dylan with her. While in Hangzhou Greg makes a really poor investment into some novelty bottle openers that play a communist tune. May’s family reunion is a disaster as it turns out the Chinese side of the family hate her mother, and therefore her. They add insult to injury when they ask Ash to be a bridesmaid at the wedding. Sean struggles to get back to the others and after a couple of false starts, ends up hitching a lift with troubled newlyweds Eugene and Kendra who are hoping to use him to revitalize their relationship. But when they attempt to spring a threesome on him, he runs off, steals their hire car and makes his own way to Hangzhou to rejoin the rest of the gang.

May and Ashley decide to do some ‘good’ by volunteering at a charity project in an orphanage in rural Vietnam. It’s not on May’s mum’s itinerary, but May manages to convince her to pay for it as it’ll be good on her CV. But May is surprised to discover that she is terrible with children. Meanwhile Dylan and Sean blag a top room in a luxury hotel by using the card of a travel writer, Sam, who they met in Episode One, on the plane over. Greg has the opportunity of romance with hospital doctor, TAM but messes it up by reacting badly to the fact that she once had leprosy. Sean notices the attraction between Dylan and Ash and jealously barges Dylan during a game of basketball, injuring him. But this seriously backfires when Ash visits Dylan in the sickbay and they end up having sex.

The gang head to a Thai beach for some R and R and a Full Moon Party. But Dylan’s ex, Lauren turns up to rekindle their relationship, and is soon dictating the gang’s activities. Hurt by how quickly Dylan has forgotten about her, Ashley spends some quality time with Sean. Sean’s hopeful this might lead to something more until Ashley reveals that she and Dylan slept together in Vietnam. May gets food-poisoning and demands that Ash stay to take care of her instead of going to the alternative, very much not Full Moon party that Lauren is taking them to. Ash gives her a sedative to get her off her back and avoid being her nurse, but when she gets back later she discovers they’ve been robbed. Lauren’s alternative party is a total bust. Greg makes a break for it and heads for the real Full Moon Party, but it’s not the same as he remembers it. Nothing is. Dylan’s conflicted about Lauren, but a moment of perfect romance presents itself and he’s overwhelmed by it and proposes.

The gang, plus Lauren who is now Dylan’s fiancée, head to the jungle for a trek. Together with Genevieve, a French hippy with terminal cancer who is working through her bucket list, and Dana, their alarmingly inexperienced guide, they set off – but tensions are high. Dylan is beginning to wonder if getting engaged at the age of 19 is a sensible idea, Greg gets bitten by a leech and becomes feverish and irrational and May and Ash aren’t speaking after the sedative incident in Episode Four. Things go from bad to worse when Lauren finds out about Dylan and Ashley slept together in Vietnam. It’s not long before they get completely lost. But when Sean is allowed to take the lead he is quickly able to find them a safe place to camp until they’re rescued. He also has a one-night stand with Dana, who finds his impressive survival skills a real turn-on. Ash is fed up with everyone blaming her for everything and decides to split off from the gang and go travelling with Genevieve. But when the jeeps arrive to take them back to safety the next day, they discover that Genevieve has died in her sleep. A distraught Ash makes it up with May. And Dylan finally sees the light about Lauren. He dumps her and embraces the gang once more.

The gang are seriously unimpressed when they arrive in Kuala Lumpur to visit Jotty, a former school mate of Greg’s who he used to play squash with. But Jotty’s charming manner, big car and stylish flat soon win them over, particularly May who makes a well thought through decision to have a spontaneous fling with him. Greg, desperate for some money after his ill-advised bottle opener investment, accepts a menial job in Jotty’s company. And Ash discovers that she’s lost her scholarship and can’t afford to go back to university, so she decides to stick around in Kuala Lumpur too and get a job. Not to be deterred, Dylan plans to continue travelling with Sean, but seeing Jotty, the self-made man, has made Sean worry that he’s wasting his time travelling when he should be growing his business. But none of Jotty’s promises turn out to be what the gang had hoped, and at the end of an eventful night in Jotty’s bar, Greg tells his old friend where he can stick his job. As a result, the gang are faced with an enormous drinks bill and only one way to pay it off: Greg versus Jotty, the squash match of the century.