Bud Abbott and Lou Costello Meet the Killer, Boris Karloff
Where to watch in US
Not currently streaming in US.
Lost Caverns Hotel bellhop Freddie Phillips is suspected of murder. Swami Talpur tries to hypnotize Freddie into confessing, but Freddie is too stupid for the plot to work. Inspector Wellman uses Freddie to get the killer (and it isn't the Swami).