After her grandmother is murdered in a home invasion, Tamsin Culver leaves her cushy programming job in San Francisco and returns to her Midwestern hometown to settle the estate. What she doesn't expect is to find out her grandmother's life-changing secret: She's not an Earth native, but an exile from another level of the Nigh-Space continuum, an adjacent reality with technology far more advanced than ours. What's more, her grandmother ruled there as an oligarch, meaning Tamsin is the heir to vast wealth only accessible by someone from her bloodline... but the enemies who tried to exterminate her family won't be happy to see her return.

Back in the Bay Area, grad student Glenn makes a startling discovery about his girlfriend Vivy. She's a secret agent for the Interventionists: an interdimensional organisation devoted to protecting the inhabitants of Nigh-Space from those trying to take advantage of less-developed worlds. When she lands in trouble, Glenn finds himself on a sapient starship in a distant level of the continuum, racing to save her. But when Glenn and Vivy's plans clash with Tamsin's, and secret connections among them all are revealed, their situation becomes catastrophically complicated.

It's a princess of Nigh-Space versus a champion of Nigh-Space in a reality-spanning adventure that ranges from alien planets to mysterious space stations to Bay Area bars, with starship battles, cyborg augmentation, abductions, snark, betrayal, and fallout both nuclear and emotional.