Confronted with a shrewd convicted killer wanting to cut a deal, the investigators gamble on calling in a disgraced former colleague to help.

Asking increasingly pointed questions, the team tries to crack a zealous defense put forth by the head of an online group that unmasks sexual predators.

With scarce evidence to guide them, the investigators question an arrogant businessman accused of rape by a woman who works for him.

Called in one by one on a Sunday, the team risks a legal entanglement when a routine interview with a convicted killer's wife takes a provocative turn.