Released 14 May 1941, King of the Zombies was intended as a vehicle for Béla Lugosi (a role for which he would’ve been perfect). Unfortunately, he was unavailable at the time, and Monogram tried to negotiate for Peter Lorre (who also would’ve been great). Finally, Henry Victor was signed shortly before filming commenced. Because of Mr. Victor’s heavy German accent, he was unable to be a leading man, and instead established himself as a character actor.
James McCarthy (Mac) (Dick Purcell), his buddy Bill Summers (John Archer), and his very funny valet Jefferson Jackson (Jeff) (Mantan Moreland) are flying from Cuba to Puerto Rico when their plane blows off-course and crashes in a storm. The trio end up on a strange island, right in the middle of a cemetery.
With nowhere else to go, they enter the first house which presents itself and meet the acquaintance of owner Dr. Miklos Sangre (Henry Victor). Though they heard a faint radio signal while still in the air, Dr. Sangre denies any radio stations on the island. He instead claims they must’ve heard something from one of the many ships passing through, and says the next ship won’t arrive for about two more weeks.
Despite Jeff’s fears and suspicions, particularly regarding creepy butler Momba (Leigh Whipper), Bill and Mac accept the offer to stay as longterm guests. Jeff meanwhile is banished to the servants’ quarters in the cellar, which connects to the kitchen. He’s delighted to make the acquaintance of pretty maid Samantha (Marguerite Whitten), but newly frightened by the ancient cook Tahama (Madame Sul-Te-Wan).
Other residents of the mansion are Dr. Sangre’s wife Alyce (Patricia Stacey) and niece Barbara Winslow (Joan Woodbury). Jeff, who’s already wise to the existence of the household’s zombies and refuses to believe Dr. Sangre’s rebuttals of their true nature, is even more alarmed by Mrs. Sangre. As Dr. Sangre explains, “She lives, yet walks in the land of those beyond.”
Everyone then gets settled for the night, but Jeff still can’t relax. When a few zombies try to attack him, he flees upstairs and tells his friends what happened. The commotion gets Dr. Sangre’s attention, and he once more insists there are no zombies and that Jeff is just imagining things. However, he does finally permit Jeff to stay in the same room as Mac and Bill.
Jeff freaks out again when he sees Mrs. Sangre coming through a wall. Mac and Bill are finally convinced he’s on the level when Jeff finds an earring she dropped on the bed, and they go to investigate. During the course of the investigation, Mac finds Barbara in the library, researching how to break her aunt’s hypnotic state.
This time, no one believes Dr. Sangre when he finds them and tries to set their minds at ease. They’re determined to get off this island as soon as possible.
These plans, however, are thrown into jeopardy when the zombies come calling again. Will they be able to escape without joining the ranks of the undead?