Scenario 1: Mossad agents, in the country posing as Canadian tourists, broke into a home where Mashaal was sleeping and injected a deadly poison into his neck. Jordanian authorities arrested two of the ten agents who were engaged in the attempt. [Source: Wikipedia]
Scenario 2: And this is the story that I had previously heard. This one took place in broad daylight. On September 25th, 1997, two Mossad agents brushed past Mashaal on his way to office and attached a device to his ear that unleashed the poison into his body. The agents quickly got into a getaway car but were captured by the police after being cornered by Mashaal’s bodyguard. They were found to be carrying Canadian passports which turned out fake. [Source: The American Jewish Yearbook 1998]
Both scenarios had the same ending though. As Mashaal lay dying in a hospital bed, a furious King Hussein demanded that Israel deliver the antidote to the untraceable poison, which at first Netanyahu refused but then turned over after increasing pressures, and Mashaal survived the attempt.
The Mossad agents in custody were later released in exchange for the release of Ahmad Yassin, the founder of Hamas who was serving a life sentence in an Israeli prison. The entire episode helped Mashaal’s rise to power in the movement.
Pretty fascinating, huh?