Malte Stierngranat was an adventurer, an engineer and an entrepeneur who was buried inside a pyramide he designed himself. And it's the disappearance of Erik, Malte's son, and his family that Carol Reed will have to investigate. Indeed, she's been contacted by George, the caretaker of the family, worried about them. And when Carol seems to be in a dead end, the boyfriend of
Malte’s granddaughter is found dead in a barn owned by the Stierngranats. The subsequent police investigation determines that his body has been there since the family vanished, and this discovery brings Carol back to unravel the mystery.