When lounge singer Dean Martin (Northam) and burlesque comic Jerry Lewis (Hayes) clicked during an impromptu pairing in 1946, neither anticipated their unparalleled success as a team. Lewis was going nowhere fast with an act built around miming to records, while Martin was making a subpar living as a crooner, sleeping on his agent's couch. Lewis had beseeched his agent to reteam him with the reluctant Martin; Lewis instigated their act and adopted the jaded pro as his unofficial big brother. Ever aloof, Martin is content to cash in on the bonanza and continue his sideline in womanizing. But as Lewis assumes more control, Martin’s mistress, Jeanne (Levering), nags him to take more credit. From bistros to radio to television, the seductive singer and the wacky stooge click with audiences. As the act takes Hollywood by storm in 1949, Lewis becomes paranoid about Martin’s popularity; psychosomatic stomach pains become his way of grabbing attention. Handsome and effortlessly charming, Martin successfully launches a solo acting career, in part to escape Lewis’s directorial aspirations and oppressive neediness. When Martin is called on the carpet by his wife, Betty (Cale), he walks out on his family; his frustration and resentment at being part of a two-headed showbiz monster only increases. Engineered by managers and agents, the last lap of the Martin-Lewis partnership is a cheerless financial arrangement, and though each triumphs after the official split in 1956, neither ever recaptures the elation of their early chemistry.