Over the course of two years following the demise of Deacon Frost, Blade (Wesley Snipes) has been on a relentless quest to locate his former mentor, Whistler (Kris Kristofferson), who somehow survived his suicide attempt. With the assistance of his new weapon designer, Scud (Norman Reedus), Blade successfully tracks down Whistler in eastern Europe, discovering him entangled with a formidable vampire gang. Through an intense interrogation of the last surviving member, Rush (Santiago Segura), Blade stumbles upon Whistler imprisoned in a tank, subjected to unspeakable torture. In a moment of triumph, Blade rescues Whistler, returning him to their lair and utilizing a cure crafted by Dr. Karen Jenson to rid him of his vampirism.
As this unfolds, a grave situation arises within the vampire ranks. A perilous new strain of vampirism, identified as the Reaper virus, is spreading like wildfire, originating from Jared Nomak (Luke Goss). These Reapers possess exceptional strength and resilience, rendering them nearly indestructible to conventional weapons, with sunlight being the only effective means of destruction. They harbor an insatiable hunger, requiring far more sustenance than ordinary vampires, and their bites turn both humans and vampires into Reapers.
In response to this escalating threat, vampire overlord Eli Damaskinos (Thomas Kretschmann) dispatches his loyal minion Asad (Danny John-Jules) and daughter Nyssa (Leonor Varela) to persuade Blade into an alliance. After realizing the Reapers pose a danger to both their kind and humanity, Blade reluctantly partners with the vampires. He joins forces with the Bloodpack, an elite unit of vampires initially formed to hunt him down. This team includes Asad, Nyssa, Reinhardt (Ron Perlman), Chupa (Matt Schulze), Snowman (Donnie Yen), Verlaine (Marit Velle Kile), her partner Lighthammer (Daz Crawford), and Priest (Tony Curran). To maintain control over Reinhardt, Blade cleverly affixes an explosive device to the back of his head.
Their mission begins in a bustling vampire nightclub, while Whistler assumes the role of a sniper, covering Scud as they navigate through the chaos. The team soon discovers the staggering capabilities of the Reapers; they are immune to silver, significantly stronger than ordinary vampires, and remarkably resistant to typical disabling injuries. Tragedy strikes when Priest falls victim to a bite, undergoes transformation, and is ultimately put down, while Lighthammer conceals his own bite. Chaos ensues as Whistler mysteriously vanishes and Scud finds himself under assault from multiple Reapers, who he fends off using UV light.
As Blade faces off against Nomak, who proves immune even to Blade's anti-coagulant spikes, their duel reaches an impasse until Nomak escapes into the daylight. When Whistler returns following the skirmish, he reveals his discovery of the Reaper Nest hidden in the sewers. In an intense scene, Nyssa dissects a deceased Reaper to glean insights, while Scud and Whistler develop ultraviolet-empowered armaments for the mission.
Upon their entry into the Reaper nest, tension rises. Lighthammer's transformation leads to the demise of Snowman, as he chases Verlaine, resulting in a tragic mutual destruction by sunlight exposure. As Chupa and Reinhardt begin to provoke Whistler, he retaliates with a Reaper pheromone, causing a horde to overwhelm and kill Chupa as he escapes. The team is beset with further losses, as Asad is pulled underwater and killed.
In a climactic turn of events, Blade employs a UV-emitting bomb that decimates the Reapers, excluding the ever-elusive Nomak. However, the situation becomes dire as Damaskinos' forces betray Blade, Whistler, and Scud. Dark secrets unravel, revealing Nomak as Damaskinos' own son, and Scud's treachery as one of Damaskinos' familiars is exposed. Blade, ever vigilant, eliminates Scud with a bomb, and with Damaskinos plotting to dissect him, Whistler manages a daring escape to free Blade, killing Damaskinos' human lawyer, Karel Kounen, in the process.
The ensuing mayhem leads Blade to the Blood pool, where he regains his strength and unleashes his fury on Damaskinos' henchmen, culminating in Reinhardt's death. Meanwhile, Nomak confronts his father, seeking vengeance, while Nyssa, driven by disillusionment, betrays Damaskinos, sealing off his only escape. Following a desperate negotiation gone awry, Nomak kills Damaskinos, and in a cruel twist, bites Nyssa, subjecting her to the Reaper virus.
In a final confrontation, Blade squares off against Nomak, engaging in an intense and brutal battle. After discovering Nomak's critical weakness through Nyssa's prior research, Blade delivers a fatal blow. With vengeance served, and compassion in his heart, Nomak drives the blade deeper into himself, ending his suffering. In a poignant moment, Blade carries the ailing Nyssa outside, granting her one last glimpse of the sun before she peacefully passes away.
With the crisis quelled, Blade journeys to London, where he hunts down Rush and exacts his final revenge.
