The Nightstalkers is a group of vampire hunters comprised of humans that appear in Blade: Trinity. They are tasked with assembling the Daystar virus in order to kill Drake and eliminate all vampires from existence.
After Blade is arrested by the FBI when he is framed for the murder of a familar (who was wearing fake vampire fangs), Abigail Whistler and Hannibal King infiltrate the FBI and rescue him when Danica Talos, Jarko Grimwood and Asher Talos prepare to kill him after he is drugged by Dr. Edgar Vance, revealed to be a familar working for them.
Blade learns that their leader is the daughter of his mentor and father figure, Whistler, and is initially reluctant to work with the Nightstalkers, viewing them as rookies and clueless about vampire hunting. It is only after learning of Drake's resurrection (one of the most powerful vampires in existence due to being the father of all modern vampires), he agrees to team up with them. Abigail, Hannibal and Blade begin to hunt down the familars as they are usually the bottom of command and the easiest to break, they encounter Drake who has murdered the real Dr. Vance and shapeshifted into him: Hannibal is injured after being stabbed in the shoulder with a silver stake and Blade pursues Drake, who kidnaps and a baby and while admiring him as a fellow warrior of the sword, he criticizes Blade for his weakness when it comes to humans.
Blade and Abigail learn that the vampires have kidnapped homeless people and placed them in medically-induced comas in a blood farm in order to keep harvesting their blood as nobody would miss homeless people to look for them. They shut down the life support and while here, Drake, in disguise as Whistler, infiltrates the Nightstalkers hideout and kills all of the members there with the exception of King and Zoe Sommerfield (who are kidnapped). King is tortured and interrogated by Danica Talos for information on Blade and despite the threat of being turned back into a vampire and locked in a room with Zoe to feed on her, King doesn't break and is rescued by Abigail and Blade, who tracked down his location from a tracker in his body. Blade takes on Drake, Abigail takes on the remaining vampires and King ends up in a fight with Jarko Grimwood, who he manages to kill by forcing him to bite into a capsule that is stuck onto his metal fang and disintegrates. Blade is overpowered by Drake and almost killed until Abigail saves him and together they mortally wound him with the Daystar virus arrows, which release the virus into the air and kill the remaining vampires, including Danica.
With the day saved, Blade's death is faked by Drake as a final "parting gift" as Drake viewed him as an honorable adversary and he goes off on his own path as the Nighstalkers continue to hunt as well.