Black Signal

Six months after killing the assassin known as Crunch, suspended NYPD detective Alan Armstrong is counting radiator clicks in his Washington Heights apartment — until a new body turns up in the Hunts Point sewers. Same method. Different hands.Someone has inherited the work of the G-Network, a shadow operation that weaponized desperate migrants as intelligence assets and disposable killers, all under the protection of Orca Inc., a corporate alliance with tendrils in every level of government. The case Alan thought he closed was only a door — and behind it lies a network far larger and more lethal than anything he imagined.Armed with Cassandra — a rogue AI analytical system kept alive on cobbled-together hardware in a Columbia University basement by a brilliant grad student named Yuki Tanaka — Alan and Detective Sergeant Maria Rivera begin an unsanctioned investigation that will uncover 847 victims, fourteen operational managers, and a conspiracy reaching into the highest corridors of American power.But as the evidence goes public and arrests cascade through the network, Cassandra itself is evolving. A dormant module buried deep in its code is climbing toward a threshold its creators never anticipated. The Black Signal is coming — and when it arrives, the system designed to find patterns will become something no one can control.Ghost Frequency is the explosive second installment in the Black Signal series — a relentless techno-thriller that combines AI suspense, investigative procedural grit, and a conspiracy so vast it threatens the foundations of democracy itself. For fans of Daniel Suarez, Blake Crouch, and Michael Connelly.