This is a very slow film, with a not very frightening monster, a rather dull romance, and some pretty unconvincing backgrounds.That said, it does have its moments of excitement, and the basic story manages to hold one's interest, if you can get through the long stretches of expository dialogue.
The parts that stay in my memory the strongest are those involving the tragic figure of archaeologist Giles Dalrymple, played by Jack Gwillim.This dignified older man has a weakness for alcohol, and as his embarrassment at being an unwilling participant in the hokey show biz presentation of the mummy by the American impresario increases, his drinking gets worse. There are a couple of truly memorable and sad scenes involving his boozing, one where a housekeeper tries to persuade her employer to eat supper, as he pours himself the latest of many drinks and insists he isn't hungry.
The other is an uncomfortably convincing scene of Giles trying to be helpful to a younger colleague, who is translating a manuscript, and Giles clumsily spills his drink on the ancient parchment. The younger archaeologist has been trying to restrain his impatience and discomfort with the awkwardness of his mentor being intoxicated, but he loses his temper and curses Giles for being a drunken old fool. The actor's look of chagrin at what he has just said is completely real, as is Giles' sad, low key response, as he looks shocked at first, but says " So I see I've lost your respect now, also", and the younger man tries to pretend he didn't mean it.
This scene is perhaps the most memorable of the entire film, and quite moving. It's a small moment in the convoluted tale of the mummy and the curse, but a striking one, nonetheless.
Having recently acquired a copy of this movie and seen it twice, I am struck by the idea that the basic storyline is rather intriguing, and might have made for a much more exciting picture. I think the main problem is that the leads are not terribly interesting personalities and/or that their characters are under-written. Imagine the possibilities if Christopher Lee had played the part of Adam Beauchamp instead of Terence Morgan, or Richard Pasco had played John. Terence Morgan gives his role a good try, but I can't help feeling that Lee would have brought a really intense, evil charisma to the part of Adam that would have made Annette's attraction to him more believable. Also, imagine the level of intensity and fire that Pasco would have brought to the role of John, with serious conflict between him and Adam over the love of Annette.
I think this is not really a bad film at all, but it could have been better, with more inspired casting.