When sixteen-year-old Dsa is given five bitcoin by her divorced father she is unimpressed: she hasn't heard of the cryptocurrency, and five of anything can't be worth very much. But a year later, when her grandparents are about to lose the farm near the Icelandic village of Dalvk in the north of Iceland, where their family has lived for centuries, quiet, unassuming Dsa is able to rescue it with the profits from her astute trading of her father's gift.
Unknown to Dsa, her mother Helga catches the cryptocurrency bug. Not only does Helga invest in Thomocoin, a new cryptocurrency sweeping Iceland, but she persuades many of her neighbours in Dalvk to invest too, taking a cut for herself.
Helga is found murdered on the hillside above the farm and Inspector Magnus Jonson investigates. Magnus realizes that Dsa, now a nineteen-year-old student, can help him unveil the shadowy forces behind Thomocoin. But torn between loyalty to her family and fear for her life, Dsa has other ideas.