The Company — K.J. Parker

A NOVEL OF WAR, FRIENDSHIP, AND BETRAYAL.

Hoping for a better life, five war veterans colonize an abandoned island. They take with them everything they could possibly need -- food, clothes, tools, weapons, even wives.

The colonists feel sure that their friendship will keep them together. But an unanticipated discovery shatters their dream and replaces it with a very different one. Only then do they begin to realize that they've brought with them rather more than they bargained for.

One of them, it seems, has been hiding a terrible secret. And when the truth begins to emerge, it soon becomes clear that the war is far from over.