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.
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.
May and Ashley decide to do some good by volunteering at an orphanage in rural Vietnam, while Dylan and Sean claim to be travel writers to blag a top room in a luxury hotel.
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.
Tensions are bubbling over when the gang get lost on a jungle trek. Some truths are revealed, and Greg gets bitten by a tick.
The gang head to Kuala Lumpur to visit Greg's old school friend Jotty. Greg gets a job opportunity that's too good to refuse, and May's decision to sow her wild oats backfires.
The gang sign up to be extras in a Malaysian zombie film. May gets an unexpected opportunity to reconnect with her Chinese roots, while things between Sean, Ashley and Dylan reach 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.
