This sounds like a scene from a 1960 or 1970s “caper” movie. Around mid-day on Tuesday, two men walked into a medieval cathedral in Strangnas, in broad daylight, stole part of the Swedish crown jewels, and then escaped across a lake by speedboat. They are reported to have stolen two gold crowns and an orb made for King Karl IX and Queen Kristina. The objects dated from the 1600s. One of the crowns was jewel encrusted.
The crowns and orb were on display in the Strangnas Cathedral, 60 kilometers (37 miles) west of the capital of Stockholm. The thieves are said to have smashed the glass case protecting the objects and then to have run to two black bicycles left outside, which they had previously stolen. They rode the bicycles a short distance to Lake Mälaren where a white speedboat was waiting for them. They escaped in the speedboat, apparently disappearing into the vast archipelago of islands in the lake west of Stockholm. Mälaren is the third largest freshwater lake in Sweden.