An epic mosaic of many interrelated characters in search of happiness, forgiveness, and meaning in the San Fernando Valley.

Although susceptible to violent outbursts, bathroom supply business owner Barry Egan (Adam Sandler) is a timid and shy man by disposition, leading a lonely, uneventful life -- partly due to the constant berating he suffers from his seven sisters. However, several events transpire that shake up Egan's mundane existence, one of which is falling in love with one sister's co-worker, Lena Leonard (Emily Watson). But the romance is threatened when Egan falls victim to an extortionist.

Freddie Quell (Joaquin Phoenix) is a troubled, boozy drifter struggling with the trauma of World War II and whatever inner demons ruled his life before that. On a fateful night in 1950, Freddie boards a passing boat and meets Lancaster Dodd (Philip Seymour Hoffman), the charismatic leader of a religious movement called the Cause. Freddie tries hard to adhere to Dodd's weird teachings and forms a close bond with his mentor, even as other members of Dodd's inner circle see him as a threat.

In a California beach community, private detective Larry "Doc" Sportello (Joaquin Phoenix) tends to work his cases through a smoky haze of marijuana. One day, Shasta, a former lover, arrives out of the blue to plead for Doc's help; it seems that Shasta's current beau, rich real-estate tycoon Mickey Wolfmann, has a wife who may be plotting to commit him to a mental hospital. When Mickey and Shasta both disappear, Doc navigates a psychedelic world of surfers, stoners and cops to solve the case.

Renowned dressmaker Reynolds Woodcock and his sister Cyril are at the center of British fashion in 1950s London -- dressing royalty, movie stars, heiresses, socialites and debutantes. Women come and go in Woodcock's life, providing the confirmed bachelor with inspiration and companionship. His carefully tailored existence soon gets disrupted by Alma, a young and strong-willed woman who becomes his muse and lover.

Veteran gambler Sydney befriends a young man named John, transforming into a Las Vegas casino champion. John falls for a prostitute, and the couple soon finds themselves in need of Sydney's help.

In the San Fernando Valley in 1977, teenage busboy Eddie Adams (Mark Wahlberg) gets discovered by porn director Jack Horner (Burt Reynolds), who transforms him into adult-film sensation Dirk Diggler. Brought into a supportive circle of friends, including fellow actors Amber Waves (Julianne Moore), Rollergirl (Heather Graham) and Reed Rothchild (John C. Reilly), Dirk fulfills all his ambitions, but a toxic combination of drugs and egotism threatens to take him back down.

The story of Gary Valentine and Alana Kane growing up, running around and going through the treacherous navigation of first love in the San Fernando Valley, 1973.