Seven for A Secret by Lyndsay Faye

Six months after the formation of the NYPD, its most reluctant and talented officer, Timothy Wilde, thinks that he knows his city’s dark practices very well. He is shocked to learn of the gruesome underworld of lies and corruption ruled by the “blackbirders,” who snatch free Northerners of color from their homes, masquerade them as slaves, and sell them South to toil as plantation property !