At Camp Tamakwa in 1972, a group of kids hike with “Unca” Lou Handler, and come upon a moose in the forest. Twenty years later, the former campers prepare to return to Tamakwa for a fall reunion after the regular summer season. Landing on the island, they are greeted by Unca Lou, who invited them back. Brad Berman, one of the returnees, encounters camp maintenance man “Stick” Coder, son of Wylie Coder. Brad observes that Wylie never liked him, and Stick concurs. Even though some of the returnees are married or paired up, Unca Lou insists the women sleep in the girls’ cabin, and the men in the boys’ cabin, and outlines a week of the sort of camp activities they enjoyed as kids. Jamie Ross asks Unca Lou how he can be expected to stay apart from his twenty-one-year-old girl friend, Gwen Daugherty, for six nights, and the counselor responds that he probably won’t be able to, but asks that he not harm any wild animals in the process. In their cabin, Jamie, Brad and his cousin, Matthew "Matt" Berman, reminisce, and wonder whatever became of Jack Belston. Matt recalls that Unca Lou kicked him out of camp. As Jennifer Morton, Kelly Berman and Gwen unpack in their cabin, Beth Warden arrives and is warmly welcomed. Later, Jack arrives. The others are happy to see him, but when he greets Beth, he apologetically says, “I should have been at Rick’s funeral.” When Unca Lou comes out to start the week’s activities, he seems surprised to see Jack. As a first step for the week, he makes his guests take a swimming test, then runs them through their paces on sailing gear and terminology. He tells the group they represent the “golden age” of the camp when everything seemed to come together. As they pair off to go sailing, Matt confides to Jack that he is glad to be away from his cousin, Brad, for a few minutes, and that he is thinking of leaving their clothing manufacturing business. At night, in the kitchen, the group snacks and smokes marijuana. Brad reminisces that Unca Lou used to patrol the camp at night and “bust” anyone he caught violating curfew. Later that evening, Brad returns from the bathroom to discover his roommates have short-sheeted his bed. In the morning, the guys play another trick on Brad, by removing toilet paper from the men’s room. At breakfast, the returnees marvel at Unca Lou’s ability to remember every camper’s name. Unca Lou recalls that he often gave kids who felt left out or lonely a “super secret Indian name.” Matt does not believe Unca Lou can remember his secret Indian name, but Lou responds, “Thundering Cloud.” Matt is amazed until he learns that Brad’s super secret Indian name and every other secret Indian names was also “Thundering Cloud.” Unca Lou confesses to the campers that this is the last summer for Camp Tamakwa, since he feels he can no longer connect with the kids. Later, Jack digs a hole near one of the cabins, looking for something he buried years before, but whatever he is looking for is not where he remembers burying it. Walking with some of the others, Jack is asked why he returned after having been kicked out of camp? He replies that Unca Lou’s call reminded him he needed to make amends. That night, after a long day, Kelly asks Matt if he has fallen out of love with her. He protests that they have come up to the camp to have a good time, but she insists they have to work things out between them. She remembers when he used to spend hours saying goodnight to Jennifer when they were kids at camp, and she always wished he had been kissing her instead. Matt gives her a perfunctory kiss and tells her to go to bed. In the men’s cabin, the guys pull another prank, sticking Brad’s hand in warm water while he sleeps, causing him to wet the bed. The next day, watching him from afar, Jennifer and Beth discuss Jack. Beth mentions that Jack was her husband Rick’s best friend, and she thinks he is in Alcoholics Anonymous now, and that is what he was referring to when he mentioned making amends. Beth also tells Jennifer she has not made love since Rick passed away. In the evening, after having sex, Gwen suggests to Jamie they could run the camp themselves, but he is not interested; and when she suggests that he is afraid of her having a baby, he tells her he likes his life and she has fifteen years before her biological clock winds down. On the grounds at night, Matt runs into Jennifer, but she gives him a peck on the cheek and goes off to bed so he won’t get into trouble with the camp counselor. Later that night, the men “raid” the girls’ dorm. Matt cannot wake Kelly, so he asks Jennifer to join him, Jack, and Beth outside while Jamie and Gwen stay behind to make love. Beth and Jack go to the boathouse, where Beth asks Jack why he was kicked out of camp. He tells her about Sam Grover, a junior counselor Unca Lou hired over the phone, only to discover when he arrived that Sam was a black man. Lou gave Sam return fare and a week’s pay and sent him home. Jack says he was forced out because he then took something from Lou designed to take him down a peg over the way he treated Sam Grover. Matt takes Jennifer to an empty cabin, and though both realize they should leave, they start to kiss, only to have Unca Lou burst in on them and escort them back to their dorms. Jack continues to dig for what he buried, and Jennifer tells Jack that Beth is interested in him. That night the campers watch a promotional film about the camp shot when they were young attendees. Later, Beth and Jack talk by a campfire, but when he tries to kiss her, Beth tells him she is not interested in him that way. At dinner, Matt asks if someone might take over running the camp. The group discusses the idea, but the dynamics of their relationships make it clear that is not likely to happen. The following day, as the others gather on the dock, Gwen rows up in a canoe and takes off the bikini Jamie gave her as a present, saying she does not believe the garment shows enough of her body off to his friends. He demands she put on some clothes, but Gwen refuses to take orders, and he walks away. At night in their dorm, Jennifer assures Kelly that, although she is lonely, she is not trying to steal Matt. The next day, Unca Lou admits to Jack that he was wrong to treat Sam Grover the way he did. When Gwen attempts to return her ring to Jamie, he grabs her roughly. Matt intercedes, and when Unca Lou sees what is going on, he suggests they take their fight to the boxing ring. Although Matt hates boxing and at first takes a beating, he knocks Jamie down and wins the fight. Then Kelly puts on Jamie’s boxing gloves and challenges her husband, telling him he cannot ignore her anymore. As Jack again sets to digging, he finally finds what he has been looking for: Unca Lou’s silver 1946 Michigan State University Class A Boxing Championship trophy. Elsewhere, Unca Lou takes Beth to the dilapidated “Everett cabin,” and tells her about Oscar and Claire Everett. When Oscar died, he wanted to be “deep sixed” in the lake. After wasting the last fifteen years of her life alone in the cabin, Claire Everett died and wanted to be dropped into the lake to be with her husband. Beth accuses Lou of making up the story, but understands it was meant for her. As the final night dance goes on, Matt and Kelly reconcile, Jamie asks Jennifer to dance, Matt reaches an agreement with his cousin Brad to leave their clothing business, Beth takes Jack out to look at the stars and seduces him, and Gwen asks Stick Coder to dance with her. At one point Brad rushes in and gets everyone to follow him to a raft at the pier to watch Beth and Jack rowing in a canoe. Then, in an act of revenge for the tricks they played on him, Brad unties the raft and sets them adrift. Unca Lou returns to his office and finds the trophy standing on his desk. As the group boards the boat for home, Matt pulls Unca Lou aside to apologize and say that he cannot take over the camp. However, Beth and Jack are not on board, and when Lou heads back he runs into them. They tell him they want to take over the camp, but do not know where they will get the money. He happily gives them the camp for free.