For Niall Chuille, it’s a geophysicist’s dream come true: to live and work on Jupiter’s volcanically active moon, Io. For his long-time partner, inner-city ER physician ‘Tig’ Tigmyre, largely-domesticated Mars is a much-preferred destination, but both are eager to get off Earth, which is beset with massive environmental and political upheaval. When Niall dies in what everyone assumes is a tragic accident while exploring a newly formed crevasse, their hasty career choices become a nightmare for Tig: she’s trapped where she never wanted to be, millions of miles from home and three years left on her contract as a mining camp doctor. She gets a surprising but brief reprieve when she’s informed that Niall’s family has arranged for her, along with two miners who’d befriended Niall on Io, to accompany his body back to Earth. Everything has been arranged by their employer, mega-miner CaelCorp—including the return trip to Io so that Tig can fulfill the remainder of her contract. But once on Earth, Tig discovers not all she meets are who they appear to be, including, as it turns out, Niall, and that in death, he’s left her a parting gift she could never have imagined.