This is a strange mix of science fiction and fantasy. A crew of a trader spaceship ended up on a planet where voodoo magic works and bad people are using it for their nefarious purposes. The ship's doctor happened to be fairly proficient in voodoo as well (while being a good guy). He might be able to save his crew as well as their host on the planet from bad guys who are really ingenuous in their attempts to remove people who happen to be in their path.
This book made me realize I am not a big fan of mixing of science fiction and fantasy together. It also has a couple of very improbable situations; still it is entertaining enough to warrant 3 star rating.