This is one of the more obscure Boris Karloff films which is a shame cause it has some charm to it. Basically Karloff is a television celebrity who specializes in debunking the supernatural. He's called by a rich hotel owner cause the new island he bought seems to have a voodoo curse. To prove it, he shows him one of his workers who has been made a zombie. Karloff poo poos the whole zombie thing even as the plastic model in the office bleeds. He takes the zombie, the doctor taking care of him, a hotel designer, his research assistant and the hotel owner's numbah one guy to go investigate the island. On the way to the island they also pick up manly man and wormy guy. Once at the island it's clear they are being followed. It's also clear the island is dangerous and filled with killer plants.
Now I said this film had some charms and does. First of Boris is great in his jovial host mode. There's a nice noir-ish feel to the characters as they bicker with each other. The build up to reaching the island was suspenseful and certainly had the viewer in a desparate state to know just the secret of the Island.
On the other hand, the plants are disappointing. The final act is also disappointing in that after all the build up there's little steak to the sizzle. As a minor point, they go on about voodoo but the island is clearly in the south pacific. They start their travel from Hawaii and pass Wake Island. So voodoo isn't quite the name for the tribal magic involved, still why be technical. A doll with a pin in its head will still be trouble.
As a remake first I'd hire Lance Hendrickson for the Boris Karloff part. The second thing I'd do hire Brad Dourif for the Elisha Cook Jr. role as Wormy Guy. Then for the script I would ramp up the character bickering even more, specially the subplot where the older "wicked" woman tries to tempt the meek research assistant into being a bad girl. We can go a lot further with this plot point than we could in 1957. Once at the island I would spend more than a buck seventy five for the killer plants. I'd also put in a twist that they were never interested in putting a hotel on the island but rather they wanted the plants for the pharmaceutical value. Finally, I'd make the end a lot bloodier clash between cultures.
Anyway, that would be my plan...