The Return of Doctor X

A pair of bizarre murders occur wherein the victims are drained of their rare Type One blood type. Reporter Walter Garrett consults with his friend Dr. Mike Rhodes which leads them to Rhodes' former mentor, hematologist Dr. Francis Flegg. Flegg is initially unhelpful, but Garrett and Rhodes notice a striking resemblance between Flegg's strange assistant, Marshall Quesne and the late Dr. Maurice Xavier in old press cuttings. After opening Xavier's grave and finding it empty, they confront Flegg. Flegg admits using his new scientific methods to bring Xavier back from the dead and has employed synthetic blood to sustain his life. However, the blood cannot replace itself, and therefore, Quesne/Xavier must seek out human victims with the rare Type One blood type contained in the formula in order to stay alive.