Tenebrae

The Serbian Brotherhood headed by a man calling himself the Viper has arrived in Chicago, a city they see as the perfect place to establish their gun and drug smuggling businesses. But when the Chicago police raid one of their bases, the Brotherhood retaliates by setting up and destroying a SWAT unit. Cailan Bane and Dan Gabriel, a former top Recon Marine sniper team and owners of Imaginarium, a video game design outfit, pitch in to help police detective Harry Sanchez track down the Viper and drive the Brotherhood out of town. Yet someone else has a keen interest in the Serbian crime organization. A mysterious figure watches the Brotherhood, intercepting their drug drops and substituting a deadly mixture of psychotropic compounds for the cocaine. The Brotherhood's efforts to develop the Chicago gangs as drug distribution partners turns into a disaster when anyone trying their cocaine dies horribly from a hallucinogenic nightmare. As Cailan and Dan converge on the Viper, their path intersects with a man who can turn the very air they breath into a nightmare death, and they don't know if he's a crusading vigilante or a cunning psychopath. The killer's cryptonym says it all; the Latin word for darkness. He is Tenebrae.