This book is so much better than the moronic movie versions that distort the plot entirely. In large measure, Shelley's imaginative book is about responsibility.
Victor Frankenstein is the student/scientist who animates the "Creature," a far more articulate being than the gutteral monster mis-named "Frankenstein" in the movies. The creature's utter loneliness drive the book. He is neither man nor beast, and his rejection by Frankenstein, after being created by him, leads to disastrous consequences.
The creature's anger is merited. Does a creator have a responsibility to that which s/he creates? The creature has no place in the world and no history - he is alone in a particularly gripping manner. In many ways, Shelley's book looks ahead to scientific discovery in general and asks the question, who is responsible?