The Mummy's Curse stars Lon Chaney, Jr. as the Mummy. No one from previous installments returns for this one. The strangeness begins right away, with the setting changing from New England to the swamps of Louisiana. With no explanation. You'd think I'd be more resigned to this kind of thing, but I spent the first bit of the film trying to figure out where the heck they were and then wondering why.
Moria says it's "almost on the verge of being interesting." 1000 Misspent Hours says it is "visibly thrown together from whatever half-formed, discarded ideas were left over from the production of the preceding films." Rotten Tomatoes gives it 57%.