In the wake of environmental catastrophe, January, once a principal in London's Royal Ballet, has become a refugee on Tharsis, the terraformed colony on Mars. In Tharsis, January's life is dictated by his status as an Earthstronger-a person whose body is not adjusted to Mars's lower gravity and so poses a danger to those born on, or naturalized to, Mars. January's job choices, housing, and even transportation options are dictated by this second-class status, and now a xenophobic politician named Aubrey Gale is running on a platform that would make it all worse: Gale wants all Earthstrongers to be surgically naturalized, a process that is always disabling and can be deadly. When Gale chooses January for an on-the-spot press junket interview that goes horribly awry, January's life is thrown into chaos, but Gale's political fortunes are damaged, too. Gale proposes a solution to both their problems: a five year made-for-the-press marriage that would secure January's future without immediate naturalization and ensure Gale's political future. But when January accepts the offer, he discovers that Gale is not at all like they appear in the press. They're kind, compassionate, and much more difficult to hate than January would wish. But as their romantic relationship develops, the political situation worsens, and January discovers Gale has an enemy, someone willing to destroy all of Tharsis to make them pay - and January may be the only person standing in the way.