Jack Packard
Janet Mitchell
Rex Kennedy
Doc Long
Leon Hartman
Det. Capt. Quinn
Louise Mitchell
Prof. Arthur Logan
Curator Raymond Halliday
Dr. Karger
Nurse
E. R. Willard
Senor Mendoza
John, butler
Quentin Mitchell
Introductory Narrator (voice)
Frank, Willard's aide
Closing-Time Museum Guard
Brophy, museum watchman