The story, which is told in the first person, centers on down-and-out actor Lawrence Smith (stage name Lorenzo Smythe, a.k.a. "The Great Lorenzo"). A brilliant actor and mimic, he is down to his last coin when a spaceman hires him to double for a public figure. It is only when he is on his way to Mars that he finds out how deeply he has been deceived: he will have to impersonate one of the most prominent politicians in the solar system (and one with whose views Smythe deeply disagrees): John Joseph Bonforte. Bonforte is the leader of the Expansionist coalition, currently out of office but with a good chance of changing that at the next general election. Bonforte has been kidnapped by his political opponents, and his aides want Smith to impersonate Bonforte while they try to find him. Bonforte is rescued, but he is in poor health due to the treatment inflicted on him during his imprisonment. This forces Smith to extend his performance, even to becoming temporary Supreme Minister and running in an election. The central political issue in the election is the granting of the vote to Martians in the human-dominated Solar System. Lorenzo shares the anti-Martian prejudice prevalent among large parts of Earth's population, but he is called upon to assume the persona of the most prominent advocate for Martian enfranchisement. Smith takes on not only Bonforte's appearance, but some aspects of his personality. At the moment of electoral victory, Bonforte dies of the aftereffects of his kidnapping, and Smythe realizes he has little choice but to assume the role for life. In a retrospective conclusion set twenty-five years later, Lorenzo has 'become' Bonforte, suppressing his own identity permanently. He has been generally successful and has carried forward Bonforte's ideals to the best of his ability. Penny (Bonforte's adoring secretary; now Smith/Bonforte's wife) says, "I never loved anyone else." At the end, Lorenzo looks back on his former life, including the prejudices he used to hold, commenting that they seem to him like they happened to someone else.