“How could you do that?”
“Had to! Science, you know!”

Historians/Archaeologists being uncareful with their findings, discover the mummy of Imhotep who was buried alive. These guys have fragile British minds, and one goes instantly mad when he sees the mummy walk away from the dig site. Unlike the Hammer version, the mummy doesn’t return as a silent grey-ragged monster but as a well-spoken Boris Karloff, who helps the remaining dudes and one of their sons figure out where to dig next. Karloff hypnotizes a hottie named Helen to make her into his immortal queen, but the other guys needlessly interfere after realizing Karloff is their lost mummy by watching flashbacks in a magical TV-pool.

Imhotep’s funeral procession as seen in the Flashback Pool:

The hottie was Zita Johann of Howard Hawks’s Tiger Shark. Her movie career was as short as Freund’s directing career – he had shot Dracula and Metropolis, and after stepping up for this movie he made Mad Love and a few others before returning to his cinematographer role. David Manners, our young hero nobody cares about, also played the hero nobody cares about in Dracula, and his dad was Arthur Byron, sadly unrelated to Mary Shelley’s buddy Lord Byron.

L-R: Byron, Johann, Karloff, Manners