Nick finds the watch left by the hunter.
In the episode Hunted, a psychopathic woman decides that the biggest game to hunt is other human beings. She therefore offers each of her targets in turn a large reward if they should survive for a half an hour. She also gives each a watch that counts down the time remaining to them.
Her first victims are homeless; then she gradually scales up to more dangerous prey. However, by that time, the police are investigating the mysterious murders. It is when Det. Nick Knight saves a biker from her—but is shot with no apparent harm—that the hunter discovers the existence of vampires.
The watch counts down the time remaining.
She decides to hunt Nick. To motivate him to participate, she kidnaps his partner, Det. Don Schanke, from the police parking lot. Inside Nick's car, she leaves her threat (on cassette) and another watch. Nick has half an hour to save Schanke, or he will be blown up by a bomb. However, to get there in time, Nick has to elude the hunter's attempts to kill him. As he seeks his partner, Nick takes the watch in order to keep track of the time as it counts down to the deadline.