All Flesh Is Grass

A classic, typically Simak work on the effects of first contact and how humans can hope to deal with aliens too strange and powerful to oppose or defeat.

The story moves along well, the setting feels familiar (if a little out of date now) and both emotions and behaviors are congruent and reasonable.

The ending comes on pretty fast, and the resolution is presented as a inevitability with little to compel the reader's agreement. A minor disappointment in an otherwise egnrossing work.