The enigmatic and mysterious head of Mansbridge Academy, and of the Mansbridge Experiment. He has his work cut out for him, not only in trying to make the Experiment work, and helping both the vampire and human students deal with their daily problems, but also in keeping the one group from snacking on the other. It is never revealed exactly what he is, though there are hints he is neither human nor vampire. Which may explain why he rarely ever seems to sleep.
- Murdoch seems impervious to many of the vampires' gifts, including Essie Rachimova's talent of hypnotic suggestion, and proves capable of subduing even an out-of-control Karl Todman.
- In the past, he fell in love with a woman whose drowning death he has always blamed himself for, and when one day her ghost comes back from the grave, it is presumed to get revenge on him. But with the help of Merrill Young and Marty Strickland(!), he realizes that her real purpose is not revenge, but to assure him that her death was not his fault, and to let go of his guilt. Once this is done, she leaves him in peace (Love's Labours Not Lost Ep. 17).