Nick Vrenna is serving time for a crime he didn't commit, locked in a facility where the guards conduct illegal experiments on inmates. When a riot triggers a catastrophic lab accident, a mutagenic substance called "Abuse" tears through the compound — turning everyone it touches into a violent monster. Nick alone appears immune. Armed with a laser gun, he fights his way through the overrun complex, determined to stop the outbreak from spreading beyond the prison walls and find a way out.