In "The Human Factor", Janette returns to Toronto to avenge the murder of her lover, Robert McDonagh, who had been an arson investigator in Montreal. She knows that his killer is one of his colleagues, Mario Larouche, whose employer is in Toronto. Probably as an insurance policy against betrayal, Larouche has hidden evidence of his employer's identity in a locker at the Civic Centre.
After shooting LaRouche and taking the key to the locker, Janette goes to the Civic Centre. However, a pair of hit men are waiting; and they try to kill her by shooting up her car. She survives, and goes to Nick's loft to enlist his aid. The following evening, the two of them return to the Civic Centre to collect the evidence.
Nick parks his car; and the two of them then take a long staircase leading to the main hall of the Civic Centre. As they go downstairs, Janette tells Nick of her time in Montreal, and how she met Robert and his son Patrick. They then come out into the hall.
After walking partway round the square, Nick and Janette come to the lockers. But, before they can get the evidence, Nick realizes that they are being watched. They leave quickly, but are followed by the hit men, who once again have been lying in wait.
They rush down the long staircase, and then down a narrow escalator that debouches at a lower level hall, where the two of them are trapped outside a steel door. From the escalator, the hit men shoot at them, hitting Janette. It is only at this moment that Nick realized that she has become mortal: the wound bleeds freely, and does not heal.
Fortunately, there is a uniformed police officer patrolling the Civic Centre. She comes running, and the hit men take off. Instead of seeing them, therefore, she spots Nick and Janette. She calls on them to stop; but Nick ignores her order. Instead, he helps Janette through the door, and to an outer exit, from where he is able to fly off with her.
Later, the hit men lure Nick and Janette to the house of Peggy Bolger, Patrick McDonagh's aunt. Through threats, they persuade them to hand over the key to the locker. They then shoot at them and set fire to the house, hoping to eliminate witnesses. Being a vampire, Nick is uninjured and able to help the hostages to escape. After returning home, he is awakened by a call by Captain Reese, who tells him to get over to the Civic Centre. The bodies of the hit men have been discovered by the lockers. The evidence about the arson ring thus is brought into the possession of the police.