Brooklyn's grittiest neighborhood delivers another gruesome crime, as a deranged killer holds a little girl hostage.

Brooklyn's grittiest neighborhood delivers another gruesome crime to Special Victims Unit detectives Danielle Foster and Carter Dobbs, this time a double homicide that quickly proves to be one of the most complex cases the 66th precinct has ever encountered.

The evidence is lacking. No one's talking. But as the killer's perverse motive, stemming from the darkest form of revenge, surfaces one unsettling photo at a time, Danny and Carter understand in an instant they're dealing with a criminal who plays God, devising his own definitions of right and wrong, and inflicting horrific punishments with chilling, religious overtones.

And he's also holding a little girl captive.

As the case becomes high-profile, the investigation takes Carter into territory that hits dangerously close to home, pushing him beyond his personal limits and drawing him into a disturbingly familiar world connected by child abduction and a past he's worked hard to forget.

Meanwhile, Danny finds herself tangled in the knots of a dark, family secret-one with twisted consequences that soon tighten like a noose around her neck-and hunting the killer, whose target shifts onto those closest to Carter, becomes a challenge she can barely face.

Carter's very identity is tested as he grapples with issues of conscience and survival in a struggle that pushes him to the very edge of the fine line between cop and criminal, and beyond. He'll need every skill he's learned to defeat his worst nightmare-and the stakes couldn't be higher.