A prime minister vanishes. A ballistic missile explodes. An Arab prince rounds up some of his relatives on corruption charges and detains them in a deluxe hotel where they sleep on cheap mattresses under ornate, corniced ceilings. If it were a Hollywood script, producers would reject the plot as fanciful, but this week’s story of greed and intrigue in a Saudi Arabia steered by its brash 32-year-old crown prince, Mohammed bin Salman, is anything but.

When Saad al-Hariri, Lebanon’s prime minister, turned up in Riyadh, the Saudi capital, last Saturday afternoon to announce his resignation on state TV no one predicted what would follow. He read the speech with the conviction of a kidnap victim, blaming Iran for destabilizing his homeland with their local partners, the Shia group Hizbollah — a message that chimes with Riyadh’s depiction of Tehran as the main source of the region’s ills. That evening, Iran-allied Houthi rebels in Yemen launched a ballistic missile towards Riyadh only for it to be blown out of the sky near the airport.

Overnight, news emerged of the arrest of princes, ministers, and tycoons, in what has developed into a probe of more than 200 people on allegations of “systematic corruption” amounting to at least $100bn — roughly equivalent to the national debt. Among them was the flamboyant billionaire Prince Alwaleed bin Talal, the global investor dubbed the “Warren Buffett of Arabia”.