After 2 years of operating on Omega, The Dark Knight comes to the Citadel in pursuit of a dangerous new drug that is about to be unleashed upon the very heart of Council Space. This will put him into an alliance with Lt. Garrus Vakarian of C-Sec's Major Crimes Unit. Together the masked Vigilante and C-Sec officer will fight back against this threat to the Citadel, but what begins as a fight against The Criminal Underworld quickly escalates into a fight against massive conspiracy that will threaten all of Council Space.