It's amazing how little you can know about your own father: After the death of Berlin resident Manfred Beier in 2002, his sons Wolf and Nils began to sort out their inheritance and came across a treasure. They found dozens of wooden boxes stacked on shelves as well as numerous chests of drawers -- similar to pharmacist cabinets and apparently custom-made. The drawers contained removable inserts, each of which had staggered rows of small drilled holes about three centimeters in diameter. Each of these holes held a roll of miniature film.