Greg leads the gang to a legendary Full Moon Party in Thailand, but an unexpected face from the past threatens to ruin everyone's fun.

The gang sign up to be extras in a Malaysian zombie film, with Greg fulfilling his childhood dream of being a policeman. The love triangle reaches an explosive climax.

Dylan is taken to a Buddhist monastery after a surprise meeting with Sam Bevan, the vengeful travel writer he impersonated in Vietnam, and Ashley and Sean confront their feelings.

The gang goes on a trek and get lost in the Malaysian jungle, where Lauren discovers the truth about Dylan and Ashley, while Sean receives unexpected romantic attention.

Sean is horrified to discover Dylan's secret plan threatens to derail their 'lads holiday' to China, but things start to look up when they meet two American girls, Ashley and May.

The gang heads to Kuala Lumpur, where Greg gets a tempting job opportunity, Ashley receives bad news from college and Dylan tries to save his friendship with Sean.

May has to go to a cousin's wedding in Hangzhou, and Ashley insists that Greg and Dylan tag along. Meanwhile, Sean hitches a lift with two creepy newlyweds, who think he can help them spice things up.

The girls volunteer at a Vietnamese orphanage, but May is surprised by the amount of hard work involved. Dylan and Sean pretend to be travel writers to get a room in a luxury hotel.