This Xenotech crossbow applies Fuse to each mercury-tipped bolt as it leaves the stock. The reaction of Fuse making contact with the mercury heats the projectile to 1300 Kelvin, which not only perforates organic targets but also drives into most solid materials. This facilitates not only long-range deadly precision, but also the ability to 'pin' a target to the wall.
After some success at momentary stabilization of Fuse, the first clinical tests administered were direct cause-and-effect trials of the substance with every element on the periodic table. Mercury (Hg 80) was a proven reactant whose effects were considered stable enough for weaponization.