Who tricked the group into believe she was dying?
The film begins with a voice-over by Lucy discussing what it's like being fat, and having skinny friends in college. She calls her friend Becky, crying and insinuating she is dying. She asks Becky to rally all of the women's college friends for one final trip to see Lucy, who now helps run Holland Lake Lodge in Condon, Montana.
Orchestrated by Becky, the circle of friends meet up in an airport in Montana. Becky brings her husband Richard and introduces him, for the first time, to commodities trader George, Grammy nominated rap producer Trevor, flight attendant Austin, and State Representative Raye who also brings his wife, Mary.  When the group is assembled a man named Sam approaches the group and tells them Lucy has sent him to drive them to the lodge where she is staying.
After arriving at the lodge, the group is greeted by an attractive blonde woman.  When no one recognizes her, Lucy reveals to her friends that it is her, no longer fat! Later at lunch, Lucy explains to her friends that she has had gastric bypass surgery and she remains four pounds away from her ideal weight.
Waking the group early the next morning, she informs them that they are going on a four-day hike in which she will drop her final four pounds of weight.  The majority of the film centers on the hiking trip. Over the course of the trip, various aspects of the lives of all of Lucy's friends are revealed.  George reveals himself as gay.  Raye and Mary are unhappy together and Mary ends up taking off her wedding ring and ending her marriage to Raye.  Similarly, Becky and Richard are unhappy in their marriage, and it is revealed that Becky is having an affair with a co-worker.
Lucy