Walter, an enthusiastic Muppet fan, embarks on a trip to Los Angeles with his brother Gary and Gary's girlfriend, Mary. While touring the dilapidated Muppet Studios, they learn from the cruel oil magnate Tex Richman that he plans to demolish the studio to drill for oil unless $10 million can be raised to save it. Determined to help, Walter, Gary, and Mary seek out Kermit the Frog, who has been living a quiet life in his mansion. After some convincing, Kermit agrees to reunite the Muppets to put on a telethon and raise the necessary funds.

Kermit and the group travel across the country, reassembling the scattered Muppet gang, who have all moved on to various lives since their heyday. Miss Piggy is now a fashion editor in Paris, Fozzie Bear performs in a Reno casino, and Gonzo runs a plumbing business. Together, they face several challenges, including skepticism from television executives about their contemporary relevance. Despite these obstacles, the Muppets prepare for their telethon, reflecting on their shared past and banding together to revive the magic and camaraderie of their glory days.