One of Oslo's largest jewelry stores is robbed, and the thieves make off with nearly 20 kilograms of pure gold, numerous precious jewels, and perhaps most importantly, the Maltese watch, valued at over five million Norwegian kroner. The robbers are apprehended, but not all the stolen items are recovered. Among the missing pieces is the Maltese watch. The threads of the heist lead directly to the cunning thief, Levi Heldonen. We meet four friends—Cecilia, Leo, On, and On's dog, Egon—in their thrilling quest to find the missing items. But the road to the truth and the Maltese watch is fraught with danger, filled with escaped convicts, mysterious guests, a dead man, secret diaries, and dark, ancient corridors leading to wartime shelters.