"Surge" is a popular and highly illegal drug produced from a mixture of Promethean Compounds and PCP. It's taken intravenously and causes a powerful high coupled with temporary enhanced physical prowess.
Surge hit the streets a few years after a water-based Promethean Compound Hydroepinine (which would become a street drug called 'Boost') produced a refined muscle enhancer that could be cut with PCP for human consumption.
Unlike its counterpart, Boost, Surge enhancing awareness and skills along with muscular preformance. For this reason, people often inject Surge before commit some criminal acts.