The Vampire

A physician whose judgment is compromised by Campbell's pills, leading to dangerous blackouts and a gradual slide into vampiric violence. His clinical exterior masks a growing willingness to cross lethal boundaries.

Paul's daughter, whose accidental substitution of vampire blood pills sparks the chain of events. She becomes a catalyst for the unfolding danger, though she remains largely unaware of its full consequences.

Paul's nurse who notices the strange changes and tries to warn others, ultimately fleeing from danger. She represents moral clarity and courage in the midst of a scientific nightmare.

Sheriff investigating the unusual deaths and disturbances in the lab. He provides practical resolve and pursues the truth as the situation spirals out of control.

Head of the university's psychiatric department and Campbell's supervisor, skeptical of Paul's claims yet entangled in the consequences of the pills. His detachment becomes a liability as events escalate.

A researcher assisting with the experiments who is found dead with puncture wounds, underscoring the escalating danger behind the scientific enterprise.

A patient with congenital heart problems whose fate highlights the stakes of medical experimentation and the vulnerability of patients under experimental medicine.

The visionary researcher whose mind-regression work and vampire-blood pills set the plot in motion, ultimately facing the consequences of his scientific hubris.