After an experimental bio-weapon is released, turning thousands into zombie-like creatures, it's up to a rag-tag group of survivors to stop the infected and those behind its release.
Former musician and gunslinger El Mariachi arrives at a small Mexican border town after being away for a long time. His past quickly catches up with him and he soon gets entangled with the local drug kingpin Bucho and his gang.
After being set-up and betrayed by the man who hired him to assassinate a Texas Senator, an ex-Federale launches a brutal rampage of revenge against his former boss.