Despite being undercover dressed as Santa Claus, Hooker is finding it hard to get into the Yuletide cheer faced with his first Christmas away from Fran and the children; Stacy too, is low on Christmas spirit, after splitting up with her boyfriend. The Christmas blues set in even deeper when a drug stakeout doesn't go to plan, allowing the main target to get away. Later, after Stacy witnesses an armed hold-up by a man and woman connected with the wanted dealer, the woman is forced to abandon her young baby at a local church. As they try and get a lead on the offenders, Stacy looks after the young baby, but Hooker, Corrigan and Romano become concerned that she may be coming to attached to it too want to give it back...

Following the bludgeoning to death of a nurse, Hooker and co. investigate the case, the latest in a series of similar murders - a string of killings that Hooker investigated years before that has recently began again, in which the attacker sends a rose to the intended victim prior to the attack. With the aid of a disabled veteran detective and a top psychiatrist, Hooker and the team investigate and find evidence that the murderer, always dressed as an old-fashioned nurse, may actually be a man. But the pattern of the killings suggests that they have less than 48 hours to catch the killer before he / she strikes again...

Hooker, Romano, Stacy and Corrigan are involved in an undercover operation to nail a large cocaine dealing ring, when a highly respected fellow officer is killed, execution-style, by the ring, who are on to him. Tracking down one of the thugs involved, Romano is badly injured by a gun-shot wound, before Hooker captures the goon, who gives the lead of a crooked bail-bondsman who is involved with the dealing. Against the wishes of a DEA, Hooker and Corrigan go undercover as drug dealers, with Stacy posing as one of their carriers, to infiltrate the dangerous ring via the bail-bondsman and catch them in the act...

A planned bust on crime lord Frank Dio results in an informant of Corrigan's being shot dead, and Dio facing getting off charge after he manages to discard the gun, but held in custody for 72 hours, giving Hooker time to try and dig up enough evidence to put him behind bars. Following up the lead of Dio's former girlfriend, a prostitute, Hooker promises to put her in protective custody until the hearing and to be given a new identity after if she agrees to testify against Dio. The girl reluctantly agrees to testify, and while Stacy takes care of her young sister, Hooker must go all out to keep her alive, shielding her from the attempts on her life by Dio's men, but a security leak within the force makes keeping the girl's whereabouts a secret impossible...

After a drug bust that nails a drug-importing ring, that leaves a corrupt Officer involved with the ring dead, Hooker gives Stacy the honour of booking the seized heroin in at the precinct. Soon after, 'Mac' Mackenzie, an old fiancé suddenly re-appears on the scene and rekindles his relationship with her. But when the seized heroin is switched for sugar, meaning the Officers have nothing to hold the captured drug dealers on, Stacy is forced to hand in her badge and her gun until a hearing over the incident. Hooker begins to suspect that Mackenzie's re-appearance is rather too coincidental and that he is somehow involved with the drug ring; But with Stacy and Mac planning to get married, can he prove his fears in time?...

A worker from the Police precinct is attacked and raped, the latest in a series of rapes and robberies where none of the victims are able to identify their attacker. Investigating, Hooker and co. find that all the victims had prior been visited by a telephone repair man, information which enables them to track down the prime suspect, who ends up being killed as the result of pursuit. But Hooker fears that the dead man was actually the attacker's apprentice and not the actual attacker – a fear that is proven when the attacks continue...

Romano is working undercover as a male stripper at a night-club where the owner is a suspect in a cocaine smuggling ring, when he witnesses his contact being shot dead. The dead girl had an incriminating photo of a key drug importer, but it is stolen by a small time criminal who wants to use it to blackmail his way into the drug operation. Before her death, the girl had sent the negative of the incriminating photo to her sister, a deaf mute; but she is attacked by the same man who stole the photograph from her sister, and has the negative snatched from her. Hooker and Romano investigate the tug-of-war over the incriminating negative as they try and identify the heads of the drug operation and put them out of business...