Ina Pelletier refuses to live. Unn Ketilsdóttir refuses to die. When a 9th century Norse chieftain takes up residence in the body of a troubled young woman named R, the last person equipped to deal with it is R's therapist — burned-out, buttoned-up Dr. Ina Pelletier, who has spent years helping other people's lives while quietly abandoning her own.Unn Ketilsdóttir — the legendary Unn the Deep-Minded, who crossed oceans, freed slaves, and founded dynasties — has no patience for the modern world's timidity. She demands to be taken seriously as a client, insists on telling her story, and begins dismantling Ina's careful self-reinvention from the inside out.Is R experiencing a psychotic break — or is Unn terrifyingly, inconveniently real? Drawn into the chaos is Dr. Snorri Grimmson, an Icelandic scholar who may be the only person alive who can explain what's happening. Whether his growing attachment to Ina is professional courtesy or something more complicated, neither of them can say. And then there is the dark figure who keeps watching.Two stories unfold in parallel: the sweeping saga of a Viking woman's extraordinary life in the medieval North Atlantic, and a contemporary collision of ancient will and modern fragility in a therapist's office. Richly researched and wickedly funny, this is historical fiction with a soul — and a 9th century woman who refuses to let anyone waste theirs.