When we first encounter Randall Burns, he has no job, no girlfriend, and no prospects for either. His closest friends are in his words "settling," not settling down, but settling -- marrying anyone just so they won't die alone.
Burns is chronically single – over forty, never married, bitter. He says he wants a relationship, maybe even a wife, but the women he meets in his hometown of Boston, are too young, too old, too shallow, too boring or, worst of all, too fat.
One day at a Barnes & Noble, he comes across a travel guidebook for single men with a special itinerary and a titillating passage on vaginal thrush. Burns is not a traveler: He hates sight-seeing, strangers, public toilets, loud noises, weird smells, and people who sweat. Eventually, the call of the thrush, his fears of dying alone, and a snarky e-mail from an old girlfriend, Ricki, compel him to take the trip.
At resorts in Venezuela and Greece, the women Burns wants don't want him. Those who do want him are too old, too fat, or too something – and now he is $6k poorer thanks to his error-riddled guidebook. As Burns is shopping for flights back to Boston, he receives another e-mail from Ricki, who is, to his surprise, following his travel blog. She's betting he's having a rotten time and won't last another week. He decides to keep going.
In South Africa, Thailand, and Vietnam, Burns continues to strike out with women while Ricki continues to write, recounting his failures as a lover, a boyfriend, and a human being. Burns finally accepts that he's going to die alone and the sooner, the better. He goes bungee jumping, eats food off filthy street carts, drinks wine made from fermented cobras, and stays in hostels infested with rats, fleas, and hipster college kids. Burns lets go of his germaphobia and his quest for a woman and actually starts to enjoy himself.
In Phnom Penh, Burns meets Ned, an American sex tourist. They party with prostitutes who are friendly, young, and slender. Burns is aroused, terrified of VD, but mostly he's aroused. When Ned says, "Think of it as very thorough check up from a very friendly nurse," Burns lets go of his fears, sleeps with some bar girls, and considers prostitution as an alternative to settling or conventional relationships. Ricki writes again. She's on antidepressants and wants to apologize and see him when he gets home after her surgery. Surgery? That day, Burns has a revelation: After traveling the world, he is convinced that Ricki is The One and has been all along.
Burns returns to Boston where Ricki is healed and waiting. At dinner, something about her has changed: she's softer, kinder, and has put on weight. Burns has also changed. He's ready to settle. Ricki removes her blazer to display her surgery -- a boob job. Burns makes a move but she shoots him down.
Months later, Burns meets a slender woman, but he isn't interested. He's realized that there are worse things in life than being single: disease, death, divorce. He's going to spend his life alone and that's OK. When a bottle of Purell falls from the woman's purse, Burns hands it to her, their eyes meet. He asks her out.