When detective-in-training Sigurdís interrupts her studies in the US to return to Iceland, after discovering that the investigation into her abusive father's death has been dropped, she's plunged into a completely new case when a controversial TV personality is murdered during the Reykjavík Marathon.

Icelandic detective-in-training Sigurdís is studying criminal psychology in the US, but her plans are thrown into disarray when she discovers that her boss and mentor, Garðar, has been fired from Reykjavík CID over his investigation into Sigurdís's father's death.

Returning to Iceland to deal with the fallout, Sigurdís finds herself pulled into a disturbing case: controversial TV personality Olga Einars has been stabbed to death during the Reykjavík Marathon. Struggling to locate a runner wearing the number 1407, who was seen near the murdered woman during the race, the police soon discover that several masked runners were wearing the same number.

As the mystery deepens, Sigurdís and her fellow detective Unnar soon learn exactly how unpopular Olga was – not just with the interviewees she humiliated on live TV, but with her own son, her business partner, a widower who insists that she had a hand in his wife's death, and her ex-husband, who died in suspicious circumstances 30 years ago…

As her exploration into Olga's past becomes ever darker and more harrowing, Sigurdís must also face the truth about her own father, whilst searching for an attacker who will go to any lengths to cover up their crimes…