Hong Kong veterans Chin Siu Ho and Richard Ng, who recently co-stared in Vampire Cleanup Department, take on the old-school vampire genre again in Bio Raiders. Famed doctor Mo Tian Shi (Richard Ng) concocts an immortality medicine to save his terminally ill daughter Xiao Xin, but it comes at a grave cost. To sustain life, she must drink human blood. Twenty years later, Mo's apprentice Li Yao Shi (Chin Siu Ho) returns to town and notices something is amiss. To hide the truth, Mo poses as a vampire and tries to shoulder the blame himself. However, Xiao Xin's uncontrollable thirst for blood drives her to even bite her own father.