The bolt-thrower was a mechanical Crossbow used by Alliance Special Forces infiltration units. It was constructed from spring steel, spun graphite, and utilized a fluffed shadowsilk bowstring to produce a weapon that was near silent, but with the piercing and stopping power of a bowcaster. Despite stopping power, the bolt-thrower had the significant disadvantage of only being able to fire one bolt at a time before a timely reloading sequence.