The producers of the original `Mummy' film obviously had not thought about a sequel. They turned the mummy, Kharis, into a pile of dust at the end and destroyed the Scroll of Toth, which the mummy used to invoke his murderous spells and control the partially reincarnated Princess Ananka.
The `Mummy's Hand' was made eight years after the original had burned the storyline bridges. Therefore, the writers had to start over and hope we weren't really paying much attention to the continuity. Not surprisingly, lots of cut footage from the original film was thrown in to set up the story. This time around, instead of a scroll in a stone chest, we now have an urn full of tana leaves.
This loose sequel introduces the value of the fluid of the tana leaf to give the mummy power (carried on into subsequent mummy films) and the mummy's murderous nightly romps to eliminate those who would find and violate the tomb of the Princess. The principal investigators this time are Dick Foran, the hero and straight man, and Wallace Ford, the formula sidekick who wisecracks his way through the movie with typical nervous bravado. The rest of the mandatory characters are the evil high priest, the older scientist, an attractive female and of course, the mummy.
This movie takes on the familiar 40's mystery formula: murders mixed with comedy relief. The original film was a classic, but the `Mummy's Hand' and the mummy films that followed through the mid 1940's quickly reverted to type. They looked more like entries in a B-movie serial than the subsequent chapters of a classic horror film story.