Dramatic jewel heists don’t just take place in movies. The most unbelievable capers can also occur offscreen, and this week, thieves in Dresden, Germany, proved that to be true.

Before 5:00 AM this morning, two thieves entered Dresden’s Royal Palace via a grilled window, smashed a display cabinet, and stole three sets of 18th-century jewelry from the Grüne Gewölbe (Green Vault). Although officers were on the scene within minutes, the thieves escaped and are still at large.

German media has described it as the biggest theft of its kind since World War II, given the value of the jewels: over $1 billion, according to Reuters.

The stolen items include diamonds and rubies belonging to an 18th-century collection of jewelry deemed to be one of Europe’s greatest collections of treasures.

According to experts, selling the stolen items would be impossible considering how unique and recognizable they are; however, they could be disassembled and melted to be sold more easily.

One of the museum’s most valuable pieces, the Dresden Green Diamond, is on loan at the Metropolitan Museum of Art in New York.