Something the Lord Made tells the story of the extraordinary 34-year partnership which begins in Depression Era Nashville in 1930, when Blalock hires Thomas as an assistant in his Vanderbilt University lab, expecting him merely to perform janitorial work. But Thomas' remarkable manual dexterity and scientific acumen shatter Blalock's expectations, and Thomas rapidly becomes indispensable as a research partner to Blalock in his first daring forays into heart surgery. The film traces the groundbreaking work the two men undertake when they move in 1941 from Vanderbilt to Johns Hopkins, an institution where the only black employees are janitors and where Thomas must enter by the back door. Together, they boldly attack the devastating heart problem of Tetralogy of Fallot, also known as Blue Baby Syndrome, and in so doing they open the field of heart surgery. The film dramatizes their race to save dying Blue Babies against the background of a Jim Crow America, illuminating the nuanced and complex relationship the two sustain. Thomas earns Blalock's unalloyed respect, with Blalock praising Thomas' surgical skill as being "like something the Lord made", and insisting that Thomas coach him through the first Blue Baby surgery over the protests of Hopkins administrators. Yet outside the lab, they remain forever separated by the racial divide. Thomas attends Blalock's parties as a bartender, moonlighting for extra income, and when Blalock is honored for the Blue Baby work at a segregated Belvedere Hotel, Thomas is not among the invited guests. Instead, he watches the proceedings from behind a potted palm at the rear of the ballroom. Critics have ascribed much of the film's power to its sensitive depiction of the disparity between their two worlds and the relative anonymity in which Thomas labored even as Blalock achieved international renown.

A man who in life avoided the limelight, Vivien Thomas remained for decades virtually unknown outside the circle of elite Hopkins surgeons he trained. Thomas' story was first brought to public attention by Washington writer Katie McCabe, who learned of his work with Alfred Blalock on the day of his death in a 1985 interview with a prominent Washington, DC surgeon who described Thomas as "an absolute legend." McCabe's 1989 Washingtonian magazine article on Thomas, "Like Something the Lord Made", generated widespread interest in the story, precipitated the making of a 2003 public television documentary on Thomas and Blalock, "Partners of the Heart", and formed the basis for the HBO film.