Mason trains his two Doberman Pinschers, Laurel and Hardy, to attack and kill anyone who hears the telephone "command" word: "Rosebud" . Plot Summary

Dr. Charles Hunter, Mason's best friend and colleague.

The dogs are actually friendly, which makes their sudden aggression toward a familiar friend suspicious.

Mason invites Hunter to his home while he is allegedly at a clinic. He calls his own house and engages Hunter in a conversation about a film. When he says the word "Rosebud," the dogs brutally attack Hunter, making it look like a tragic accident caused by aggressive pets.