Munich native Ursula Glück is shot and killed in her sleep during a dream honeymoon on the Inca Trail. Her husband, Jona Kepler, the sole witness, claims they were attacked by two men. Back in Munich, homicide detectives investigate, but suspicion falls on Kepler. With no motive or evidence, the truth remains elusive. How do you solve a murder on the remote Inca Trail, with no witnesses, no weapon, and no evidence? Chief Inspector Rita Berg faces this challenge after Ursula Glück is killed during an alleged robbery. Her husband, Jona Kepler, claims innocence, but suspicion lingers. Despite a lack of motive, Berg keeps digging. Eighteen months later, in New York, she uncovers a life insurance policy worth a million dollars. The investigation picks up speed, leading her team to Peru, where conflicting accounts, a matching suspect, and another robbery deepen the mystery. After a three-year investigation, new evidence emerges, pointing to Kepler. The prosecution has no doubt anymore and hands the man over to the judiciary, though he continues to protest his innocence until the very end. A murder with no witnesses, no weapon, and no evidence – Chief Inspector Rita Berg must solve the unsolvable on the remote Inca Trail.