An urgent call brings FBI agent Kate Hayden back to San Antonio, the scene of her violent past. A brutal new murder shows hallmarks of a serial killer nicknamed the Samaritan. Tricky part is, Kate already caught him. Did she make an error, or is it a copycat? Paired with homicide detective Theo Mazur, Kate faces an enemy who knows her intimately. When a second body is found, the mode of death is identical to a different case that Kate had worked on. The closer they come to the killer there is only one rule: don't believe everything you see.