Katie ignores Greg's warning and takes Anna-Kat through a terrifying zombie-themed maze at the annual Halloween carnival. Once inside, Katie quickly regrets her decision and sends Anna-Kat to find help. Meanwhile, Greg has entered a pumpkin carving contest and is ready to go head-to-head against the previous year's winners.

Frank works to vindicate a detective accused of using excessive force. Danny and Baez track down the killer responsible for the death of a rapper's bodyguard. Jamie is skeptical about a relationship between Espinoza and a rookie officer.

Sandi Toksvig and Alan Davies are joined by Jo Brand, Phill Jupitus and Prue Leith.

Cooper’s moral compass is tested when an officer whom he served with as a young man, long presumed to be dead, resurfaces as a POW.

Sam and the Brides arrive at Fort Collins, where Hansen reveals a secret for raising the Dark One.