Instruct: Classify a given review into positive or negative sentiment.
Query: A man from Earth brought in to rescue an alien world

This appears to be the very first book of a long series. The magic is good, and it can be exhausting...possibly even fatal. The main key to magic seems to be being able to visualize clearly what you want it to do, which means a bit of understanding of science goes a long way...probably why the main character was brought in in the first place since science is pretty rare on the planet.