The Rambaldi Firebomb was a powerful microwave EMP-Bomb composed of ancient artifacts. Sloane and Sark captured the mathematician Neil Caplan since they knew he was smart enough to construct such a device. At first, Caplan said it couldn't work, but after Sloane stole a magnetometer from Amcore Bank, he was able to build it. According to Sark, the bomb was very unstable and had to be managed carefully. Sark was even wary of using it because he stated that if Caplan was even off just a little bit, it could backfire and kill him too (Firebomb).