A detective gets abducted shortly after getting an award for his undercover work in Malaysia, so Frank has Danny search for the Malaysian drug lord who's holding the detective hostage. Elsewhere, Henry does a ride-along with Jamie.
Danny learns about voodoo while investigating a stabbing committed by someone in costume on Halloween. Meanwhile, Garrett reveals a deep secret to Frank; and Erin and Nicky take Danny's sons trick-or-treating.
Danny investigates the murder of a college student who may have been dealing drugs. Elsewhere, Jamie reexamines his life after meeting up with a former law-school buddy; and Erin tries to allow Nicky to be more independent.