Greg Sestero, an aspiring actor, meets the enigmatic and eccentric Tommy Wiseau in an acting class in San Francisco. Despite Wiseau's unconventional methods and appearance, the pair form an unlikely friendship. Tommy suggests they move to Los Angeles to pursue their dreams, and they take off in hopes of making it big in Hollywood. However, they struggle to find work and face constant rejection. Frustrated and determined, Tommy decides to write a script for his own movie, "The Room," and convinces Greg to star in it.

With no prior experience, Tommy takes on the roles of writer, director, producer, and lead actor. He spares no expense and funds the project himself, leading to a chaotic and baffling production process. As filming progresses, the cast and crew grow increasingly frustrated with Tommy's erratic behavior and questionable decisions. They question whether the movie will ever be completed or make any sense. Through the turmoil and tenuous moments on set, Greg remains loyal to Tommy, albeit with growing doubts about their endeavor's success. The story explores themes of friendship, ambition, and the pursuit of artistic vision against all odds.