In 2022, a group of Israeli intelligence officers came up with a plan to pull off one of the most cunning and deadly acts of spycraft in modern history. Their target? Hezbollah, a powerful militia group in Lebanon that has long been a thorn in Israel’s side. Hezbollah is known for being extremely careful and paranoid about Israeli surveillance, so this plan had to be nearly flawless—and it was.

The idea was to turn a simple communication device, something as ordinary as a pager, into a d...