In opening minutes of “Mr. and Mrs. Smith”—Donald Glover and Francesca Sloane’s minor-key remix of the 2005 film starring Brad Pitt and Angelina Jolie as married, duelling assassins—the series obliterates its source material. A good-looking couple on the run take a final stand, exchanging a passionate kiss as they prepare to face down assailants. Both are immediately gunned down. The real show begins: one with dark humor and a millennial sensibility reflective of its co-creator and star. Brangelina’s characters were suburbanite yuppies with his-and-hers sinks, the new John (Glover) and Jane Smith (Maya Erskine) embody their generation’s emotional and economic malaise. Their firm recruits C.I.A. rejects and their job interviews are conducted by a machine; their duties are relayed through a chat box; and they never meet their handler. In the wake of their first mission, Jane speculates about their employer. They meet after they have been “wed” by the company. The Smiths aren’t lovers who discover they’re both killers but killers who discover they’re in love. Their fumblings toward genuine intimacy amid the trappings of a fake relationship make for some of the series’ best early scenes. Glover and Erskine rend their characters believably prickly, awkward, and tender by turns. The Prime Video remake also quickly establishes an eagerness to go somewhere edgier than a broad studio action-comedy might have dared. The show acknowledges real relationship milestones and decision-making that compound with implausible speed. In a different world, they might have been management consultants, but they are manipulated by a pitiless institution. The strains of romantic melancholy ring hollow, and the blues of a spy with a debt he can never repay eventually drown out.