Hmmm, what a dilemma.
The weapon you need is being held by a greedy business man. I see two options to get him to simply hand it over, both appeal to his greed. Tell him he'll be branded a hero for providing the tool that saves everyone, and the new attention will bring massive sales to his company. If he doesn't hand it over, he'll be branded a traitor for siding with the enemy, all of his property and possibly his life are forfeit. Easy to see which path is more profitable. Any third option is only a short term gain, with a long term loss. Not good for business.